Clipper Tutorial: a Guide to Open Source Clipper(s)/Printable version

Programming With Harbour and Other Free xBase Languages?"

D:\harbourcode>PATH c:\hb32\bin;D:\wscite

 function MAIN
 * This is an example
 clear
 ?"Hello, the weather is fine today"
 ?"(this is a test of HbIDE)"
 wait && will show "Press any key to continue..." and prevent the console window to close immediately
 return

 function MAIN
 * This is an example
 clear
 ?"Hello, the weather is fine today"
 return nil

function MAIN

function MAIN
FUNCTION main
FuNcTiOn mAiN

* This is an example

* This is a comment...
// ...and so is this...
&& ...and this.
/* This is an example of the fourth commenting style,
which may span over several lines.*/

clear

#command CLS                        => Scroll() ; SetPos(0,0)
#command ?  [<explist,...>]         => QOut( <explist> )

? "Hello, the weather is fine today"

? "Hello, the weather is fine today"
? 'Hello, the weather is fine today'
? [Hello, the weather is fine today]

return nil

&& hello world without commands and main
Scroll() ; SetPos(0,0)
QOut( "Hello world" )

hbrun hello.prg

? "Hello world"

QUIT

? "A"

HB_FUNC( PRINTA )
{
	static const HB_BYTE pcode[] =
	{
		36,1,0,176,1,0,106,2,65,0,20,1,7
	};

	hb_vmExecute( pcode, symbols );
}

hbmk2 /gh printA.prg
harbour /gh printA.prg

hbrun printA.hrb

 && example of compilation command
 && A:\>c:\hb32\bin\hbmk2 -quiet -oc:\hbcode\test.exe test.prg -run

 && please note that this example has not a MAIN function

 && an example of string concatenation
 ? "Hello" + " " + "World!"

 && let us do now a few numerical computations, integer numbers are a good starting point
 ? 5+13
 ? 12*8

 ? 3/2
 SET DECIMALS TO 15
 sqrt2=sqrt(2) && computing the square root of 2...
 ? sqrt2 && ... and printing it

 && ? caporetto 
 && if the line above was not commented, the compiler would issue the two following lines
 && Error BASE/1003  Variable does not exist: CAPORETTO
 && Called from TEST(8)

 && as xBase is not good at history, let us revise it: http://www.historyofwar.org/articles/battles_caporetto.html,  http://www.firstworldwar.com/battles/caporetto.htm
 && we can then assign the correct date to this war
 caporetto := ctod("10-24-1917")

 a := date() && system date
 ? a + 1 && will print tomorrow's date 
 ? a - caporetto && this will tell us how many days have passed since Caporetto's battle (difference between two dates)

 SET DECIMALS TO 2
 ? (a - caporetto) / 365
 ?? " years have passed since Caporetto's battle"

 ? 1+1=3
 && it will print ".F.", that is, "FALSE" (of course...)

 && The following two instructions should be discussed to expand on the subject of operator precedence
 ? 1/2+2^3*sqrt(25)-3^2
 ? 1/2+2^3*(sqrt(25)-3^2)

a := 1+1
? a
a := "abc"
? a

?a+1

123       => a number
"123"     => a string

sTest:="fun"
?sTest, STUFF(sTest,2,1,"a")
&& => fun fan

Lower()   Convert uppercase characters to lowercase
Upper()   Converts a character expression to uppercase format
Chr()     Convert an ASCII code to a character value
Asc()     Convert a character to its ASCII value
Len()     Return the length of a character string or the number of elements in an array
At()      Return the position of a substring within a character string

AsciiSum()   Finds the sum of the ASCII values of all the characters of a string
Soundex()    is a character function that indexes and searches for sound-alike or phonetic matches
CHARONE()    Search and remove repeating characters
CHARONLY()   Remove non-standard characters
CHAROR()     "OR" bytes in a string

#include "Inkey.ch"
DO WHILE .T.
WAIT "" TO cChar
?? " ", Asc( cChar )
IF ( LastKey() == K_ESC )
EXIT
ENDIF
ENDDO

&& First we print the values of two expressions with the exponentiation operator
? 3**3**3 && is 19683
? 3**(3**3) && is 7625597484987

&& Then we let our compiler tell us if they are the same
? 3**3**3 = 3**(3**3) && result is .F.

&& We've a look at how our compiler deals with overflow and underflow...
? 9**9**9
&& ***********************
? 1/9**9**9
&& 0.00
? -(9**9**9)
&& ***********************

date()-1000000
&& today my outputs are:
?date()
&& ==> 05/15/19
?date()-365000 && more or less 1000 years
&& ==> 01/13/20
set century on && we change an option...
?date()-365000 && ... and try ageing
&& ==> 01/13/1020
?date()-1000000 && more or less 2700 years (i.e. the results should be around 700 B.C.)
&& ==> 00/00/00
?ctod("31-12-9999")+1
&& ==> 00/00/00

store 7 to n && an alternate way of an assignment (dates back to dBase II)
?sqrt(sqrt(n))^2^2=n
&& the result is .F.
set decimals to 15
?sqrt(sqrt(n))^2^2
&& 7.000000000000003

to_be=.T. && is it true?
?to_be .OR. .NOT. to_be
&& .T.
to_be=.T. && is it false?
?to_be .OR. .NOT. to_be
&& .T.

Function MAIN()
LOCAL number
INPUT "Key in a number: " TO number
IF number = 0
?? "Congratulations, you keyed the fabolous number "
ENDIF
? number
RETURN

Function MAIN()
LOCAL number
INPUT "Key in a number: " TO number
IF number % 2 = 0
   ? "You keyed in an even number"
ELSE
   ? "You keyed in an odd number"
ENDIF
RETURN

Function MAIN()
LOCAL number
INPUT "Key in a number: " TO number
IF number % 2 = 0
   ? "You keyed in an even number"
   ? "I can prove it:"
   ? "the result of ",number," % 2 = 0 is ", number % 2 = 0
ELSE
   ? "You keyed in an odd number"
   ? "I can prove it:"
   ? "the result of ",number," % 2 = 0 is ", number % 2 = 0
ENDIF
RETURN

function MAIN
LOCAL nNumber := 0
//
INPUT "Key in a number: " TO nNumber
//
?? "Your number is "
IF nNumber < 50
? "less than 50"
ELSEIF nNumber = 50
? "equal to 50"
ELSE
? "greater than 50"
ENDIF

   ? Time()
   // CToN source is numconv.prg, library is libct.
   IF CToN( SubStr( Time(), 1, 2 ) ) < 18
      ? "Good day"
   ELSE
      ? "Good evening"
   ENDIF

WAIT "Key in a letter: " TO char
IF  char = "a" .OR. char = "A" .OR. char = "e" .OR. char = "E" .OR. ;
         char = "i" .OR. char = "I" .OR. char = "o" .OR. char = "O" .OR. ;
         char = "u" .OR. char = "U"
? char, " is a vowel"
ELSE
? char, " is not a vowel"
ENDIF

   WAIT "Key in a letter: " TO char
   IF  char $ [aeiouAEIOU]
      ? char, " is a vowel"
   ELSE
      ? char, " is not a vowel"
   ENDIF

 && Function MAIN LOCAL number, sum, n 
 && An anonymous contributor renamed the variable "num" into "number", increasing this short program readability, but the line above would give
 && Error E0030  Syntax error "syntax error at 'LOCAL'"
 Function MAIN
 LOCAL number, sum, n
 CLS 
 ? "Let's sum up the first n odd numbers." 
 INPUT "How many numbers shall I sum up? " TO n 
 sum=0 
 number=1 
 DO WHILE number <= 2*n    
  sum=sum+number    
  number=number+2 
 ENDDO 
 ? "The sum requested is ", sum

LOCAL a := 10
LOCAL lMore := .T.

   DO WHILE lMore
      ? 'value of a: ', a
      a := a + 1
      lMore := ( a != 20 )
   ENDDO

LOCAL a := 10
LOCAL lMore := .T.

   DO WHILE lMore
      ? 'value of a: ', a
      a := a + 1
      lMore := .NOT. ( a = 20 ) && or, in alternative, lMore := ! ( a = 20 )
   ENDDO

 DO WHILE .T. 
 ? "I won't stop." 
 ENDDO

 CLEAR
 FOR I := 1 TO 8
   FOR J := 1 TO 8
    ?? I*J
   NEXT
 NEXT

 CLEAR
 FOR I := 1 TO 10  
   FOR J := 1 TO 10   
     @i,j*4 SAY  I*J PICTURE "999"  
   NEXT
 NEXT

LOCAL cContinue := "N"
DO WHILE cContinue = "N"

ACCEPT "What's your opinion? " TO cOpinion
?""
?? "NO!! According to me, on the contrary: "
FOR i := Len( cOpinion ) TO 1 STEP -1
??SubStr( cOpinion, i, 1 )
NEXT

WAIT "Tell me, do you have any other opinions to discuss with me? (Y/N) " TO cContinue
cContinue := Upper( cContinue )
IF cContinue = "N"
? "Ok, then. "
ELSE
? "In this case let me go."
ENDIF
ENDDO

 i = 2
 myMacro = "i + 10"
 i = &myMacro && will execute "i+10"
 ? i          && will print "12"

ACCEPT "Please enter the first number: " TO cNumber1
ACCEPT "Please enter the second number: " TO cNumber2

WAIT "Enter operation: " TO cOperation && we get a single character for the operation

? Number1+cOperation+Number2+"="       && we print the operation and an equal sign
? &(Number1+cOperation+Number2)        && and the result on the following line, evaluating the string as it appeared on the line above

Please enter the first number: 12
Please enter the second number: 23.5
Enter operation: -
12-23.5=
       -11.5

 && C:\hb32\bin\hbmk2 -quiet -oc:\hbcode\months.exe months.prg -run
 DECLARE months [12]
 ? LEN (months) && the function LEN() shows how many items an array has
 && We shall now load some data into our arrays
 PRIVATE month_names: = {"January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December"}
 PRIVATE months: = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31} && for simplicity we do not consider leap years

 && Let us make some output (using a FOR loop - see below)
 FOR I: = 1 TO LEN (months)
 ? month_names [i], "is", months [i], "days long."
 NEXT

&& compile with ''hbmk2 averaging.prg -lhbmisc''
PROCEDURE MAIN

   LOCAL n, sum := 0, average    && let's initialize the variables
   aNumbers := {}                && and an array without elements

   ? "enter a list of integer numbers, and a non-number when you are finished"
   WHILE .T.                     && we begin an endless loop
      ACCEPT "next element: " TO item
      IF IsDec( item )           && the function IsDec() from the libmisc library checks if we have entered a number
         AAdd ( aNumbers, item ) && if we did, then we add the number as a new element to the array
         sum := sum + &item      && (and we update the sum of the elements in our array)...
      ELSE
         EXIT                    && ...if we did not, we quit this loop
      ENDIF
   ENDDO

   average := sum / Len( aNumbers ) && we compute the average of the values in the array

   ?
   ? "to average the array you must correct each element by adding to it the corresponding value below"
   ?
   FOR n := 1 to LEN ( aNumbers )
      ?? AVERAGE - aNumbers[n]
   NEXT
RETURN

  FOR EACH n in aNumbers        && FOR EACH is a more modern control flow statement Harbour syntax
     ?? AVERAGE - &n
  NEXT

 aFruitSalad:={"peaches", "plums"}
 AAdd ( aFruitSalad, "onions" ) && we add onions
 ADel(aFruitSalad, 3) && on second thought, onions don't mix well: we remove them
 local f; for each f in aFruitSalad; ?? f," " ;  next && we print our ingredients
 && => peaches  plums  NIL

Harbour provides a function, hb_ADel, which accepts a third Boolean element and (if it's .T.) shrinks the array.

PROCEDURE MAIN

   LOCAL n, sum := 0, average    && let's initialize the variables
   local bError := errorblock ( { |oError| break ( oError ) } )
   aNumbers := {}                && and an array without elements

   ? "enter a list of integer numbers, and a non-number when you are finished"
   WHILE .T.                     && we begin an endless loop
      BEGIN SEQUENCE
      ACCEPT "next element: " TO item
         AAdd ( aNumbers, &item ) && if we did, then we add the number as a new element to the array
         sum := sum + &item      && (and we update the sum of the elements in our array)...
      RECOVER
         EXIT                    && ...if we did not, we quit this loop
      END SEQUENCE
   ENDDO

   average := sum / Len( aNumbers ) && we compute the average of the values in the array

   ?
   ? "to average the array you must correct each element by adding to it the corresponding value below"
   ?
   FOR n := 1 to Len ( aNumbers )
      ?? average - aNumbers[n]
   NEXT
RETURN

Error           Provides objects with information about runtime errors
Get             Provides objects for editing variables and database fields
TBrowse         Provides objects for browsing table-oriented data
TBColumn        Provides the column objects TBrowse objects

Error class       Provides objects with information about runtime errors
CheckBox class    Provides objects for creating checkboxes
Get class         Provides objects for editing variables and database fields
ListBox class     Provides objects for creating list boxes
MenuItem class    Provides objects for creating menu items
PopUpMenu class   Provides objects for creating pop-up menus
PushButton class  Provides objects for creating push buttons
RadioButto class  Provides objects for creating radio buttons
RadioGroup class  Provides objects for creating radio button groups
Scrollbar class   Provides objects for creating scroll bars
TBColumn class    Provides objects for browsing table-oriented data
TBrowse class     Provides the column objects TBrowse objects
TopBarMenu class  Provides objects for creating top menu bars

FUNCTION cels2f( tempCelsius )
tempFahrenheit := (tempCelsius*1.8 + 32)
RETURN tempFahrenheit

FUNCTION MAIN()
? cels2f(100)
? cels2f(0)

/**
 * by choosing better variable names this function becomes self-explanatory
 */
function convert_Celsius_to_Fahrenheit(Celsius_temperature)
  return Celsius_temperature * 1.8 + 32

FUNCTION MAIN()
? convert_Celsius_to_Fahrenheit(100)
? convert_Celsius_to_Fahrenheit(0)

PROCEDURE Main
 // Random number between 0.01 and 0.99
 ? HB_Random()
 // Random number between 0.01 and 9.99
 ? HB_Random(10)
 // Random number between 8.01 and 9.99
 ? HB_Random(8,10)
 // Random integer number between -100 and 100
 ? HB_RandomInt(-100,100)
 RETURN

FUNCTION cels2f( tempCelsius )

   tempFahrenheit := (tempCelsius*1.8 + 32)
   number := number + 1

   RETURN tempFahrenheit

FUNCTION MAIN()

   number := 0
   ? cels2f( 100 )
   ? cels2f( 0 )
   ? number

      212.0
       32.0
        2

/* Work on the following.
 * hbformat was run on this piece of code
 * need to provide comments, nest more functions and procedures to help figuring what goes on with scope modifiers
 */

STATIC x := 9

   ? x
   A()
   ? x
   B()
   ? x
   C()
   ? x
   D()
   ? x
   E()
   ? x

PROCEDURE A

   LOCAL x := 10

   ? "x from A=", x

   RETURN

PROCEDURE B

   PRIVATE x := 5

   ? "x from B=", x

   RETURN

PROCEDURE C

   PUBLIC x := -1

   ? "x from C=", x

   RETURN

PROCEDURE D

   ? "x from D before updating value=", x

   x := 12

   ? "x from D=", x

   RETURN

PROCEDURE E

   ? "x from E=", x

   RETURN

         9
x from A=         10
         9
x from B=          5
         9
x from C=          -1
         9
x from D before updating value=          -1
x from D=         12
         9
x from E=         12
         9

x := 9

   ? x
   A()
   ? x
   B()
   ? x
   C()
   ? x
   D()
   ? x
   E()
   ? x

PROCEDURE A

   LOCAL x := 10

   ? "x from A=", x

   RETURN

PROCEDURE B

   PRIVATE x := 5

   ? "x from B=", x

   RETURN

PROCEDURE C

   PUBLIC x := -1

   ? "x from C=", x

   RETURN

PROCEDURE D

   ? "x from D before updating value=", x

   x := 12

   ? "x from D=", x

   RETURN

PROCEDURE E

   ? "x from E=", x

   RETURN

         9
x from A=         10
         9
x from B=          5
         9
x from C=         -1
        -1
x from D before updating value=         -1
x from D=         12
        12
x from E=         12
        12

// adapted from "An example of static local variable in C" (from Wikipedia Static_variable)
FUNCTION func()
	static x := 0
	/* x is initialized only once, the first time func() is called */
	x := x+1
	? x
RETURN

FUNCTION main() 
	func() // calls func() a first time: it prints 1
	func() // value 1 was preserved; this time it prints 2
	func() // prints 3
	func() // prints 4
	func() // prints 5

 && compile with ''hbmk2 computepi.prg -lhbct''
 PROCEDURE MAIN
 SET DECIMAL TO 14
 ? 4 * ATAN (1)

  #pragma BEGINDUMP
  #include <extend.h>
  #include <math.h>
   HB_FUNC( ATAN )
   {
      double x = hb_parnd(1);
      hb_retnd( atan( x ) );
   };     
 #pragma ENDDUMP
 SET DECIMAL TO 14 
 ? 4 * ATAN (1)

/* DON'T USE THIS FILE FOR NEW HARBOUR C CODE */
/* This file is provided to support some level of */
/* Harbour compatibility for old Clipper C extension code */

Write a program that prints the numbers from 1 to 100. But for multiples of three print “Fizz” instead of the number and for the multiples of five print “Buzz”. For numbers which are multiples of both three and five print “FizzBuzz”.

FOR I = 1 TO 100
    FLAG = 0
    IF I % 5 = 0 
        FLAG = 1
        ?? "Fizz"
    ENDIF
    IF I % 3 = 0 
        FLAG = 1
        ?? "Buzz"
    ENDIF
    IF FLAG = 0 
        ?? I
    ENDIF
    ?? ", "
NEXT

   // we'll declare and load random numbers from 1 to 100 in an array
   DECLARE arrayToSort [12]
   FOR I = 1 TO 12
      arrayToSort [I] = Int( HB_Random( 1,101 ) )
   NEXT

   // we review our array
   FOR I = 1 TO 12
      ?? arrayToSort [I]
   NEXT

   // we'll do Exchange Sort as described in http://www.ee.ryerson.ca/~courses/coe428/sorting/exchangesort.html
   // where there is also a nice animation showing how it works! :)
   for i := 2 TO Len(arrayToSort)
      for j := Len(arrayToSort) TO i step -1
         IF arrayToSort [j - 1] > arrayToSort [j] 
		TEMP := arrayToSort [j - 1]
		arrayToSort [j - 1] := arrayToSort [j]
		arrayToSort [j] := TEMP
	 ENDIF
      NEXT
   NEXT

   ?
   ? "Sorted array:"
   ?

   // we look at our sorted array
   FOR I = 1 TO 12
      ?? arrayToSort [I]
   NEXT

PROCEDURE ExchangeSort(array)
   // we'll do Exchange Sort as described in http://www.ee.ryerson.ca/~courses/coe428/sorting/exchangesort.html
   // where there is also a nice animation showing how it works! :)
   for i := 2 TO Len(array)
      for j := Len(array) TO i step -1
         IF array [j - 1] > array [j] 
		TEMP := array [j - 1]
		array [j - 1] := array [j]
		array [j] := TEMP
	 ENDIF
      NEXT
   NEXT
RETURN

FUNCTION MAIN
   // we'll declare and load random numbers from 1 to 100 in an array
   DECLARE arrayToSort [12]
   FOR I = 1 TO 12
      arrayToSort [I] = Int( HB_Random( 1,101 ) )
   NEXT

   // we review our array
   FOR I = 1 TO 12
      ?? arrayToSort [I]
   NEXT

   ExchangeSort(arrayToSort) // we call the procedure and pass to it our array called arrayToSort

   ?
   ? "Sorted array:"
   ?

   // we show the array is sorted
   FOR I = 1 TO 12
      ?? arrayToSort [I]
   NEXT

FUNCTION main
 ? factorial(10)
RETURN 0

FUNCTION factorial(n)
    IF n = 0
        RETURN 1
    ELSE
        RETURN n * factorial(n - 1)
    ENDIF
RETURN -1

FUNCTION cels2f( tempCelsius )
tempFahrenheit := (tempCelsius*1.8 + 32)
RETURN tempFahrenheit

Cels2F := { | celsius | Fahrenheit := (Celsius * 1.8 + 32) } // our first codeblock

? Eval(Cels2F,100)
? Eval(Cels2F,0)

PROCEDURE MAIN(file)
    ? MEMOREAD(file)
RETURN

 && it was done this way at the Dot Prompt
 && we can type this interactively in hbrun
 CREATE TMPNAMES
 USE TMPNAMES
 APPEND BLANK
 REPLACE FIELD_NAME WITH "NAME"
 REPLACE FIELD_TYPE WITH "C"
 REPLACE FIELD_LEN WITH 15
 APPEND BLANK
 REPLACE FIELD_NAME WITH "ADDRESS"
 REPLACE FIELD_TYPE WITH "C"
 REPLACE FIELD_LEN WITH 30
 CLOSE
 CREATE NAMES FROM TMPNAMES && https://www.itlnet.net/programming/program/Reference/c53g01c/ngc785e.html
 ERASE TMPNAMES.DBF && we get rid of the temporary file

 CLEAR
 ? "First Sample Program"
 SELECT 1
 USE NAMES
 APPEND BLANK
 REPLACE NAME WITH "MIKE BROWN"
 REPLACE ADDRESS WITH "ROME STREET, 56"
 CLOSE && this line is missing in my PC GUIDE but is needed in a compiled Harbour program
 QUIT

 local aStruct := { { "NAME",    "C", 15, 0 }, ;
                    { "ADDRESS", "C", 30, 0 }}
 REQUEST DBFCDX
 dbCreate( "namesdb", aStruct, "DBFCDX", .t., "NAMESDB" )
 && http://www.fivetechsoft.com/harbour-docs/api.html
 USE NAMESDB
 NAMESDB->(DbAppend())
 NAMESDB->NAME := "MIKE BROWN"
 NAMESDB->ADDRESS := "ROME STREET, 56"

 USE NAMES
 LIST DATE(), TIME(), NAME, ADDRESS

use test
browse()

locate for first="Ted"
? recno()

 .aDbf := {} 
 .AADD(aDbf, { "MOVIEID", "C", 6, 0 })
 .AADD(aDbf, { "TITLE", "C", 30, 0 }) 
 .AADD(aDbf, { "GENRE", "C", 30, 0 }) 
 .AADD(aDbf, { "YEAR", "N", 4, 0 }) 
 .AADD(aDbf, { "LEADACTOR", "C", 30, 0 }) 
 .AADD(aDbf, { "PRICE_EUR", "N", 5, 2 })
 .DBCREATE("videolib", aDbf)

 Database Files    # Records    Last Update     Size
 videolib.dbf              0    09/15/21         227
PROCEDURE EnterMovieData
    LOCAL MOVIEID, TITLE, GENRE, YEAR, LEADACTOR, PRICE_EUR

    @ 5, 10 SAY "Movie Code:" GET MOVIEID
    @ 7, 10 SAY "Movie Title:" GET TITLE
    @ 9, 10 SAY "Genre:" GET GENRE
    @ 11, 10 SAY "Year of Production:" GET YEAR
    @ 13, 10 SAY "Leading Actor:" GET LEADACTOR
    @ 15, 10 SAY "Price in Euro:" GET PRICE_EUR

    // Save data
    INSERT INTO videolib VALUES (MOVIEID, TITLE, GENRE, YEAR, LEADACTOR, PRICE_EUR)
RETURN

1,"Jurassic Park","azione",1993,"Jeff Goldblum",35.99
2,"Jumanji","avventura",1995,"Robin Williams",8.49 
3,"Navigator","fantascienza",1986,"Joey Cramer",11.39 
4,"Mortal Kombat","azione",1995,"Christopher Lambert",10 
5,"Karate Kid 4","azione",1994,"Hilary Swank",4.9 
6,"Ritorno al futuro","fantascienza",1985,"Michael J. Fox",6.95 
7,"2001: Odissea nello Spazio","fantascienza",1968,"Keir Dullea",7.9 
8,"Il pianeta proibito","fantascienza",1956,"Leslie Nielsen",9.99 
9,"Interstellar","fantascienza",2014,"Matthew McConaughey",6.95
10,"Prometheus","fantascienza",2012,"Michael Fassbender",7

.replace genre with "science fiction" for genre="fantascienza"
.replace genre with "action" for genre="azione"
.replace genre with "adventure" for genre="avventura"

list - a verb
title, leadactor, year - an expression list
for year < 2000 - a condition

** report.prg
use videolib
index on genre+title to iReport
set printer on
set printer to 'rMovie.html'
?[<html><body>]
?[<h1>],"Movie Report",[</h1>]
?[<table>]
?[<tr><th>Movie Code<th>Genre<th>Title<th>Price in Euro</tr>]
do while .not. eof()
  ?[<tr>]
  ?[<td>],movieid
  ?[<td>],genre
  ?[<td>],title
  ?[<td>],price_eur
  ?[</tr>]
 skip
enddo

h1 {
  display: block;
  font-size: 2em;
  margin-top: 0.67em;
  margin-bottom: 0.67em;
  margin-left: 0;
  margin-right: 0;
  font-weight: bold;
  margin: auto;
  width: 50%;
  border: 3px solid green;
  padding: 10px;
  text-align: center;
  font-family: Arial, Helvetica, sans-serif;
  background-color: lightgreen;
}

table, th, td {
  border: 1px solid black;
  margin: auto;
  width: 75%;
  border: 3px solid green;
  padding: 10px;
}
table.center {
  margin-left: auto;
  margin-right: auto;
}
th, td {
  padding: 10px;
  width: 25%;
  text-align: center;
}
th {
  padding: 10px;
  width: 25%;
  font-family: Arial, Helvetica, sans-serif;
  border: 3px solid blue;
  background-color: lightblue;
}

iReport  ntx     2048  09/15/21
movies   txt      605  09/15/21
report   prg      414  09/15/21
rMovie   htm     1290  09/15/21
styles   css      743  09/15/21
titlesor ntx     2048  09/15/21
videolib dbf     1287  09/15/21

       SELECT 1
       USE Books
       SELECT 2
       USE Customers
       SELECT 3
       USE Loans
       SELECT Books

 /*
  * $Id: testdbf.prg 1792 1999-11-10 10:17:19Z bcantero $
  */

 function main()

   local nI, aStruct := { { "CHARACTER", "C", 25, 0 }, ;
                          { "NUMERIC",   "N",  8, 0 }, ;
                          { "DOUBLE",    "N",  8, 2 }, ;
                          { "DATE",      "D",  8, 0 }, ;
                          { "LOGICAL",   "L",  1, 0 }, ;
                          { "MEMO1",     "M", 10, 0 }, ;
                          { "MEMO2",     "M", 10, 0 } }

   REQUEST DBFCDX

   dbCreate( "testdbf", aStruct, "DBFCDX", .t., "MYALIAS" )

   ? "[" + MYALIAS->MEMO1 + "]"
   ? "[" + MYALIAS->MEMO2 + "]"
   ? "-"
   MYALIAS->( dbAppend() )
   MYALIAS->MEMO1 := "Hello world!"
   MYALIAS->MEMO2 := "Harbour power"
   ? "[" + MYALIAS->MEMO1 + "]"
   ? "[" + MYALIAS->MEMO2 + "]"
   MYALIAS->( dbAppend() )
   MYALIAS->MEMO1 := "This is a test for field MEMO1."
   MYALIAS->MEMO2 := "This is a test for field MEMO2."
   ? "[" + MYALIAS->MEMO1 + "]"
   ? "[" + MYALIAS->MEMO2 + "]"
   MYALIAS->NUMERIC := 90
   MYALIAS->DOUBLE := 120.138
   ? "[" + Str( MYALIAS->DOUBLE ) + "]"
   ? "[" + Str( MYALIAS->NUMERIC ) + "]"

   ? ""
   ? "Press any key..."
   InKey( 0 )

   ? ""
   ? "Append 50 records with memos..."
   for nI := 1 to 50
      MYALIAS->( dbAppend() )
      MYALIAS->MEMO1 := "This is a very long string. " + ;
                        "This may seem silly however strings like this are still " + ;
                        "used. Not by good programmers though, but I've seen " + ;
                        "stuff like this used for Copyright messages and other " + ;
                        "long text. What is the point to all of this you'd say. " + ;
                        "Well I am coming to the point right now, the constant " + ;
                        "string is limited to 256 characters and this string is " + ;
                        "a lot bigger. Do you get my drift ? If there is somebody " + ;
                        "who has read this line upto the very end: Esto es un " + ;
                        "sombrero grande rid¡culo." + Chr( 13 ) + Chr( 10 ) + ;
                        "/" + Chr( 13 ) + Chr( 10 ) + "[;-)" + Chr( 13 ) + Chr( 10 )+ ;
                        "\"
   next
   MYALIAS->( dbCommit() )

   ? "Records before ZAP:", MYALIAS->( LastRec() )
   ? "Size of files (data and memo):", Directory( "testdbf.dbf" )[1][2], ;
      Directory( "testdbf.fpt" )[1][2]
   MYALIAS->( __dbZap() )
   MYALIAS->( dbCommit() )
   ? "Records after ZAP:", MYALIAS->( LastRec() )
   ? "Size of files (data and memo):", Directory( "testdbf.dbf" )[1][2], ;
      Directory( "testdbf.fpt" )[1][2]
   ? "Value of fields MEMO1, MEMO2, DOUBLE and NUMERIC:"
   ? "[" + MYALIAS->MEMO1 + "]"
   ? "[" + MYALIAS->MEMO2 + "]"
   ? "[" + Str( MYALIAS->DOUBLE ) + "]"
   ? "[" + Str( MYALIAS->NUMERIC ) + "]"
   ? "Press any key..."
   InKey( 0 )
   dbCloseAll()

   dbCreate( "testdbf", aStruct,, .t., "MYALIAS" )

   for nI := 1 to 10
      MYALIAS->( dbAppend() )
      MYALIAS->NUMERIC := nI
      ? "Adding a record", nI
      if nI == 3 .or. nI == 7
         MYALIAS->( dbDelete() )
         ? "Deleting record", nI
      endif
   next
   MYALIAS->( dbCommit() )

   ? ""
   ? "With SET DELETED OFF"
   ? "Press any key..."
   InKey( 0 )

   MYALIAS->( dbGoTop() )
   do while !MYALIAS->( Eof() )
      ? MYALIAS->NUMERIC
      MYALIAS->( dbSkip() )
   enddo

   SET DELETED ON
   ? ""
   ? "With SET DELETED ON"
   ? "Press any key..."
   InKey( 0 )

   MYALIAS->( dbGoTop() )
   do while !MYALIAS->( Eof() )
      ? MYALIAS->NUMERIC
      MYALIAS->( dbSkip() )
   enddo

   ? ""
   ? "With SET DELETED ON"
   ? "and  SET FILTER TO MYALIAS->NUMERIC > 2 .AND. MYALIAS->NUMERIC < 8"
   ? "Press any key..."
   InKey( 0 )

   MYALIAS->( dbSetFilter( { || MYALIAS->NUMERIC > 2 .AND. MYALIAS->NUMERIC < 8 }, ;
                           "MYALIAS->NUMERIC > 2 .AND. MYALIAS->NUMERIC < 8" ) )
   MYALIAS->( dbGoTop() )
   do while !MYALIAS->( Eof() )
      ? MYALIAS->NUMERIC
      MYALIAS->( dbSkip() )
   enddo

   SET DELETED OFF
   ? ""
   ? "With SET DELETED OFF"
   ? "and  SET FILTER TO MYALIAS->NUMERIC > 2 .AND. MYALIAS->NUMERIC < 8"
   ? "Press any key..."
   InKey( 0 )

   MYALIAS->( dbSetFilter( { || MYALIAS->NUMERIC > 2 .AND. MYALIAS->NUMERIC < 8 }, ;
                           "MYALIAS->NUMERIC > 2 .AND. MYALIAS->NUMERIC < 8" ) )
   MYALIAS->( dbGoTop() )
   do while !MYALIAS->( Eof() )
      ? MYALIAS->NUMERIC
      MYALIAS->( dbSkip() )
   enddo

   ? "dbFilter() => " + dbFilter()
   ? ""

   ? "Testing __dbPack()"
   ? "Records before PACK:", MYALIAS->( LastRec() )
   ? "Size of files (data and memo):", Directory( "testdbf.dbf" )[1][2], ;
      Directory( "testdbf.dbt" )[1][2]
   SET FILTER TO
   MYALIAS->( __dbPack() )
   MYALIAS->( dbCommit() )
   ? "Records after PACK:", MYALIAS->( LastRec() )
   ? "Size of files (data and memo):", Directory( "testdbf.dbf" )[1][2], ;
      Directory( "testdbf.dbt" )[1][2]
   ? "Press any key..."
   InKey( 0 )
   ? "Value of fields:"
   MYALIAS->( dbGoTop() )
   do while !MYALIAS->( Eof() )
      ? MYALIAS->NUMERIC
      MYALIAS->( dbSkip() )
   enddo
   ? ""

   ? "Open test.dbf and LOCATE FOR TESTDBF->SALARY > 145000"
   ? "Press any key..."
   InKey( 0 )
   dbUseArea( ,, "test", "TESTDBF" )
   locate for TESTDBF->SALARY > 145000
   do while TESTDBF->( Found() )
      ? TESTDBF->FIRST, TESTDBF->LAST, TESTDBF->SALARY
      continue
   enddo
   ? ""
   ? "LOCATE FOR TESTDBF->MARRIED .AND. TESTDBF->FIRST > 'S'"
   ? "Press any key..."
   InKey( 0 )
   dbUseArea( ,, "test", "TESTDBF" )
   locate for TESTDBF->MARRIED .AND. TESTDBF->FIRST > 'S'
   do while TESTDBF->( Found() )
      ? TESTDBF->FIRST, TESTDBF->LAST, TESTDBF->MARRIED
      continue
   enddo

 return nil

USE Customer SHARED NEW
clear
@  1, 0 SAY "CustNum" GET Customer->CustNum PICT "999999" VALID Customer->CustNum > 0
@  3, 0 SAY "Contact" GET Customer->Contact VALID !empty(Customer->Contact)
@  4, 0 SAY "Address" GET Customer->Address
READ

Simple checkbook entry and edit program
Use the Checkbook file, indexed on Check number
USE CHECKS

DO WHILE .t.
DONE = 'D'
CLEAR
@ 1,0 SAY "New Check (N), Old Check (O), Done (D), List(L)" ;
GET DONE PICT "!"
READ

DO CASE
  CASE DONE='L'
LINE = 2 
GOTO TOP
DO WHILE .NOT. EOF()
   IF LINE=2
   	CLEAR
   	@ 0, 1 say "Date    Number       Name"
   	@ 1, 1 say "  $$$     Clr  Catgy Description"
   ENDIF
				*   DATE    NUMBER    NAME
				*    AMT      CLR CAT DESC

   @ LINE  , 1 SAY CHECKDATE 	&&   MM/DD/YY
   @ LINE  ,12 SAY CHECKNO	&&   NNNNNNNN
   @ LINE  ,22 SAY RECNO()	picture "(9999)"
   @ LINE  ,30 SAY CHECKNAME	&&   CHAR 30
   @ LINE+1, 3 SAY CHECKAMT	picture "99999.99"
   @ LINE+1,14 SAY CHECKCLR	&& X
   @ LINE+1,18 SAY CHECKCAT	&& XX
   @ LINE+1,25 SAY CHECKDESC	&& Char 30

   LINE = LINE + 2
   IF LINE>22
       	Wait "Enter a key to continue"
	LINE = 2
   ENDIF
   SKIP
    enddo
IF LINE>0
       ACCEPT "Enter a key to continue" TO DONE
ENDIF
    LOOP

   CASE DONE='D' 
    USE
    EXIT

   CASE DONE='O'
        REQNO = 0
        CLEAR
        @ 1, 0 SAY "Record Number: " GET REQNO Picture "###"
        READ
    IF REQNO>RECCOUNT()
            ? "Check beyond end of file"
	WAIT "   Press any key"
            LOOP
        ENDIF
    Goto reqno
        LDATE = checkdate
        LNO   = checkno
        LDESC = checkdesc
        LNAME = checkname
        LAMT  = checkamt
        LCLR  = checkclr
        LCAT  = checkcat

   CASE DONE='N'
        APPEND BLANK
        LDATE = date()
        LNO   = '    '
        LDESC = space(30)
        LNAME = space(30)
        LAMT  = 0.0
        LCLR  = "N"
        LCAT  = '  '

    OTHERWISE
        ? CHR(7)
        LOOP
ENDCASE

Now enter Check info or edit it
done = 'N'
DO WHILE done='N'

  	Make date into editable string

EDATE = DTOC(LDATE)
CLEAR
@  1,  0  SAY "Check no.:"          GET  LNO
@  1, 30  SAY "Date:"	            GET  EDATE  Pict "99/99/99"
@  1, 60  SAY "Record number: "+str(RECNO(), 3)
@  3,  0  SAY "Check to:"           GET  LDESC
@  4,  0  SAY "Check Description:"  GET  LNAME
@  6,  0  SAY "Amount of Check:"    GET  LAMT   pict "99999.99"
@  8,  0  SAY "Check Cleared?"	    GET  LCLR
@  8, 22  SAY "Check Catagory:"	    GET  LCAT
READ

  @  10, 0  Say "All ok (Yes/No/Cancel) ?"  get DONE  pict "!"

READ
LDATE = CTOD(EDATE)
ENDDO
IF DONE='Y'
REPLACE checkdate WITH LDATE, checkno   WITH LNO,    ;

checkdesc WITH LDESC, checkname WITH LNAME,  ;
checkamt  WITH LAMT,  checkclr  WITH LCLR,   ;

checkcat  WITH LCAT
ENDIF
ENDDO

? LASTREC()
DELETE RECORD 4
PACK
? LASTREC()

     &&  This example demonstrates a typical ZAP operation in a network
     &&   environment:

        USE Sales EXCLUSIVE NEW
        IF !NETERR()
           SET INDEX TO Sales, Branch, Salesman
           ZAP
           CLOSE Sales
        ELSE
           ? "Zap operation failed"
           BREAK
        ENDIF

USE Clients NEW
INDEX ON Name TO Clients UNIQUE

FSTNAME	LSTNAME
John   	Doe
John   	Doe
John   	Doe
Jane   	Doe

SELECT 1
USE ind
? FILE("ind.ntx")
INDEX ON FstName TO ind
? FILE("ind.ntx") // we verify that a NTX file has been created

? distance1d(4,-3)
? distance2d(2,-3,-1,-2)
? distance3d(1,1,1,4,4,4)

        FUNCTION distance1d( x1, x2 )
           RETURN sqrt((x2-x1)^2)

        FUNCTION distance2d( x1,y1,x2,y2 )
           RETURN sqrt((x2-x1)^2+(y2-y1)^2)

        FUNCTION distance3d( x1,y1,z1,x2,y2,z2 )
           RETURN sqrt((x1-x2)^2+(y1-y2)^2+(z1-z2)^2)

#include "hbclass.ch"

   CREATE CLASS Point1D

   VAR Abscissa    // the abscissa of our point

METHOD New( Abscissa )    // Constructor

METHOD Distance( Point )

   ENDCLASS

   CREATE CLASS Point2D INHERIT Point1D

   VAR Ordinate    // the ordinate of our point

METHOD New( Abscissa, Ordinate )    // Constructor

METHOD Distance( Point )

   ENDCLASS

   CREATE CLASS Point3D INHERIT Point2D

   VAR Zcoord    // the Z-coordinate of our point

METHOD New( Zcoord )    // Constructor

METHOD Distance( Point )

   ENDCLASS

&& Constructors Zone
METHOD New( Abscissa ) CLASS Point1D

   ::Abscissa := Abscissa

   RETURN Self

METHOD New( Abscissa, Ordinate ) CLASS Point2D

   ::Abscissa := Abscissa
   ::Ordinate := Ordinate

   RETURN Self

METHOD New( Abscissa, Ordinate, Zcoord ) CLASS Point3D

   ::Abscissa := Abscissa
   ::Ordinate := Ordinate
   ::Zcoord := Zcoord

   RETURN Self

&&Distances Methods

METHOD Distance( Point ) CLASS Point1D

   RETURN Sqrt( ( Self:Abscissa - Point:Abscissa ) ^ 2 )

METHOD Distance( Point ) CLASS Point2D

   RETURN Sqrt( ( Self:Abscissa - Point:Abscissa ) ^ 2 + ( Self:Ordinate - Point:Ordinate ) ^ 2 )

METHOD Distance( Point ) CLASS Point3D

   RETURN Sqrt( ( Self:Abscissa - Point:Abscissa ) ^ 2 + ( Self:Ordinate - Point:Ordinate ) ^ 2 + ( Self:Zcoord - Point:Zcoord ) ^ 2 )

PROCEDURE Main()

   FirstPoint := Point1D():New( 3 )
   SecondPoint := Point1D():New( - 3 )
   ? FirstPoint:Abscissa
   ? FirstPoint:Distance( SecondPoint )
   ThirdPoint := Point2D():New( 2, - 3 )
   FourthPoint := Point2D():New( - 1, - 2 )
   ? ThirdPoint:Distance( FourthPoint )
   FifthPoint := Point3D():New( 1, 1, 1 )
   SixthPoint := Point3D():New( 4, 4, 4 )
   ? FifthPoint:Distance( SixthPoint )

   RETURN

  ? FifthPoint:Distance( SixthPoint )

FUNCTION Distance ( Point1, Point2 )
   RETURN Sqrt( ( Point1:Abscissa - Point2:Abscissa ) ^ 2 + ( Point1:Ordinate - Point2:Ordinate ) ^ 2 + ( Point1:Zcoord - Point2:Zcoord ) ^ 2 )

   ? Distance( FifthPoint, SixthPoint )

   [CREATE] CLASS <cClassName> [ FROM | INHERIT <cSuperClass1> [, ... ,<cSuperClassN>] ]
             [ MODULE FRIENDLY ] [ STATIC ] [ FUNCTION <cFuncName> ]

   [HIDDEN:]
      [ CLASSDATA | CLASSVAR  | CLASS VAR <DataName1>]
      [ DATA | VAR  <DataName1> [,<DataNameN>] [ AS <type> ] [ INIT <uValue> ]
             [[EXPORTED | VISIBLE] | [PROTECTED] | [HIDDEN]] [READONLY | RO] ]
      ...
      [ METHOD <MethodName>( [<params,...>] ) [CONSTRUCTOR] ]
      [ METHOD <MethodName>( [<params,...>] ) INLINE <Code,...> ]
      [ METHOD <MethodName>( [<params,...>] ) BLOCK  <CodeBlock> ]
      [ METHOD <MethodName>( [<params,...>] ) EXTERN <funcName>([<args,...>]) ]
      [ METHOD <MethodName>( [<params,...>] ) SETGET ]
      [ METHOD <MethodName>( [<params,...>] ) VIRTUAL ]
      [ METHOD <MethodName>( [<params,...>] ) OPERATOR <op> ]
      [ ERROR HANDLER <MethodName>( [<params,...>] ) ]
      [ ON ERROR <MethodName>( [<params,...>] ) ]
      ...
   [PROTECTED:]
      ...
   [VISIBLE:]
   [EXPORTED:]
      ...

   [FRIEND CLASS <ClassName,...>]
   [FRIEND FUNCTION <FuncName,...>]

   [SYNC METHOD <cSyncMethod>]

   ENDCLASS [ LOCK | LOCKED ]

 #include "hbclass.ch"

 PROCEDURE Main()

    LOCAL oPerson

    CLS

    oPerson := Person():New( "Dave" )

    oPerson:Eyes := "Invalid"

    oPerson:Eyes := "Blue"

    Alert( oPerson:Describe() )

    RETURN

 CREATE CLASS Person

    VAR Name INIT ""

    METHOD New( cName )
    METHOD Describe()

    ACCESS Eyes INLINE ::pvtEyes
    ASSIGN Eyes( x ) INLINE iif( HB_ISSTRING( x ) .AND. x $ "Blue,Brown,Green", ::pvtEyes := x, Alert( "Invalid value" ) )

    PROTECTED:

    VAR pvtEyes

 ENDCLASS

 // Sample of normal Method definition
 METHOD New( cName ) CLASS Person

    ::Name := cName

    RETURN Self

 METHOD Describe() CLASS Person

    LOCAL cDescription

    IF Empty( ::Name )
       cDescription := "I have no name yet."
    ELSE
       cDescription := "My name is: " + ::Name + ";"
    ENDIF

    IF ! Empty( ::Eyes )
       cDescription += "my eyes' color is: " + ::Eyes
    ENDIF

    RETURN cDescription

   hFood := { => }
   hFood["Cornflakes"] := "370"
   hFood["Spaghetti"] := "101"
   hFood["Beef"] := "280"
   hFood["Ham"] := "240"
   hFood["Broccoli"] := "32"
   hFood["Grapefruit"] := "32"
   hFood["Spinach"] := "8"
   hFood["Chocolate"] := "500"
   ACCEPT "Enter a food: " TO cFood
   IF hb_HHasKey( hFood, cFood )
      ? "&cFood is " + hFood[cFood] + " calories per 100 grams"
   ELSE
      ? "&cFood: information not available"
   ENDIF
LOCAL month
hMonths := { "January" => 31, "February" => 28, "March" => 30,  "April" => 30, "May" => 31, "June" => 30, "July" => 31, "August" => 31, "September" => 30, "October" => 31, "November" => 30, "December" => 31 }

FOR EACH month in hMonths
   ? month:__ENUMKEY()
   ?? month:__ENUMVALUE()
NEXT

LOCAL letter, ditdah
hMorseCode := { => }

hMorseCode[ "a" ] := ".-"
hMorseCode[ "b" ] := "-..."
hMorseCode[ "c" ] := "-.-."
hMorseCode[ "d" ] := "-.."
hMorseCode[ "e" ] := "."
hMorseCode[ "f" ] := "..-."
hMorseCode[ "g" ] := "--."
hMorseCode[ "h" ] := "...."
hMorseCode[ "i" ] := ".."
hMorseCode[ "j" ] := ".---"
hMorseCode[ "k" ] := "-.-"
hMorseCode[ "l" ] := ".-.."
hMorseCode[ "m" ] := "--"
hMorseCode[ "n" ] := "-."
hMorseCode[ "o" ] := "---"
hMorseCode[ "p" ] := ".--."
hMorseCode[ "q" ] := "--.-"
hMorseCode[ "r" ] := ".-."
hMorseCode[ "s" ] := "..."
hMorseCode[ "t" ] := "-"
hMorseCode[ "u" ] := "..-"
hMorseCode[ "v" ] := "...-"
hMorseCode[ "w" ] := ".--"
hMorseCode[ "x" ] := "-..-"
hMorseCode[ "y" ] := "-.--"
hMorseCode[ "z" ] := "--.."
hMorseCode[ "0" ] := "-----"
hMorseCode[ "1" ] := ".----"
hMorseCode[ "2" ] := "..---"
hMorseCode[ "3" ] := "...--"
hMorseCode[ "4" ] := "....-"
hMorseCode[ "5" ] := "....."
hMorseCode[ "6" ] := "-...."
hMorseCode[ "7" ] := "--..."
hMorseCode[ "8" ] := "---.."
hMorseCode[ "9" ] := "----."

nDotDuration := 4 && The dot duration is the basic unit of time measurement in Morse code transmission and we set it to 4/18 seconds
bPlayMorse := {| cCurrent| if ( cCurrent = ".", Tone( 480, nDotDuration ), Tone( 480, nDotDuration * 3 ) ) }

ACCEPT "Enter message: " TO message
IF message == "" && if no message we use a default one
  message := "The quick brown fox jumps over a lazy dog" && an English-language pangram — a sentence that contains all of the letters of the alphabet
ENDIF

? "Converting '"+Upper( message )+"' in Morse..."

FOR EACH letter in Lower( message )
  ? Upper(letter)+" "
    IF letter==" " 
      Tone( 0, nDotDuration * 7 ) && a long pause between words...
    ELSE
      FOR EACH ditdah in hMorseCode[ letter ]
        ?? ditdah
        Eval( bPlayMorse, ditdah )
      NEXT
    ENDIF
  Tone( 0, nDotDuration * 3 ) && ... and a short pause between letters
NEXT

dir *.dbf

dir ?.dbf
dir ??.dbf

.{1,2}\.dbf

LOCAL cRegEx := "[aeiou]"
WAIT "Key in a letter: " TO char
? char + " is" + iif( hb_regexLike( cRegEx, char, .F. ), "", " not" ) + " a vowel."

PROCEDURE MAIN

   LOCAL n, sum := 0, average    && let's initialize the variables
   LOCAL reNumber := "-?[0-9]+(\.?[0-9]+)?" && and a regular expression that matches numbers (optionally with a decimal point and a sign)
   aNumbers := {}                && and an empty array

   ? "enter a list of integer numbers, and a non-number when you are finished"
   WHILE .T.                     && we begin an endless loop
      ACCEPT "next element: " TO item
      IF hb_RegExLike ( reNumber, item ) && we replace IsDec() with hb_RegExLike()
         AAdd ( aNumbers, val(item) ) && if we did, then we add the number as a new element to the array
         sum := sum + val(item)      && (and we update the sum of the elements in our array)...
      ELSE
         EXIT                    && ...if we did not, we quit this loop
      ENDIF
   ENDDO

   average := sum / Len( aNumbers ) && we compute the average of the values in the array

   ?
   ? "to average the array you must correct each element by adding to it the corresponding value below"
   ?
   FOR n := 1 to LEN ( aNumbers )
      ?? AVERAGE - aNumbers[n]
   NEXT
RETURN

PROCEDURE MAIN

   LOCAL n, sum := 0, average    && let's initialize the variables
   aNumbers := {}                && and an array without elements

   ? "enter a list of integer numbers, and a non-number when you are finished"
   WHILE .T.                     && we begin an endless loop
   ACCEPT "next element: " TO item
      TRY
         AAdd ( aNumbers, &item ) && if we did, then we add the number as a new element to the array
         sum := sum + &item      && (and we update the sum of the elements in our array)...
      CATCH
         EXIT                    && ...if we did not, we quit this loop
      END
   ENDDO

   average := sum / Len( aNumbers ) && we compute the average of the values in the array

   ?
   ? "to average the array you must correct each element by adding to it the corresponding value below"
   ?
   FOR n := 1 to LEN ( aNumbers )
      ?? AVERAGE - aNumbers[n]
   NEXT
RETURN

FUNCTION One
   ? "Running function One"
   RETURN

PROCEDURE Two
   ? "Running procedure Two"
   RETURN

PROCEDURE MAIN

   // Display menu choices.

   @ 3, 25 PROMPT "First choice"
   @ 4, 25 PROMPT "Second choice"

   // Get menu key.
   MENU TO choice

   // Perform an action based on your menu choice.
   DO CASE
   CASE choice = 0
      RETURN
   CASE choice = 1
      DO One
   CASE choice = 2
      DO Two
   ENDCASE

   RETURN

// display a two line menu with status line at the bottom
// let the user select favorite day
SET MESSAGE TO 24 CENTER
@ 10, 2 PROMPT "Sunday" MESSAGE "This is the 1st item"
@ 11, 2 PROMPT "Monday" MESSAGE "Now we're on the 2nd item"
MENU TO nChoice
DO CASE
CASE nChoice == 0           // user press Esc key
QUIT
CASE nChoice == 1           // user select 1st menu item
? "Guess you don't like Mondays"
CASE nChoice == 2           // user select 2nd menu item
? "Just another day for some"
ENDCASE

Procedure ClickTest()
  Main.Button_1.Caption := "Test done"
Return

Library	URL	Notes	Tutorial/Documentation URL
HbQt	https://sourceforge.net/projects/qtcontribs/	see \hb30\contrib\hbqt (QtContribs includes HbQt, HbIDE & HbDBU)	http://www.elektrosoft.it/tutorials/hbqt/hbqt.asp
HMG	https://sites.google.com/site/hmgweb/ http://sourceforge.net/projects/hmg	RAD	https://sites.google.com/site/hmgweb/tutorial http://www.hmgforum.com/hmgdoc/data/index.htm
Harbour MiniGUI Extended Edition	http://www.hmgextended.com/ https://hmgextended.org/	RAD	http://www.hmgextended.com/files/manual/index.html http://www.hmgextended.com/files/winreport/index.html
wxHarbour	http://sourceforge.net/projects/wxharbour/	bindings for wxWidgets Last Update: 2016-08-24
ooHG	https://oohg.github.io/
Marinas-GUI	http://marinas-gui.org/	a wrapper for Harbour with Qt	http://www.marinas-tools.com.ar/
HwGUI	http://sourceforge.net/projects/hwgui/	Last Update: 2019-06-11	http://www.kresin.ru/en/hwgdoc.html
T-Gtk GUI for [x]Harbour	https://sourceforge.net/projects/t-gtk/	Last Update: 2019-06-24
WoopGUI - A Win32 OOP GUI Library for Harbour	http://woopgui.sourceforge.net/	Last updated: 2002/05/22
xhgtk	https://sourceforge.net/projects/xhgtk/
HBUI	https://github.com/RJopek/HBUI
hbgi	https://github.com/tuffnatty/hbgi

Clipper Tutorial: a Guide to Open Source Clipper(s)/Printable version

Foreword

Getting Acquainted

Open Source and Licenses

Software Piracy and Source Code Sharing

What do we refer to when we say 'database'?

Some Curiosities, Digressions, and a Little History

Clipper Sailboats

The Decline of Commercial xBase

Other Sites to Visit & Files to Download

Getting Started

Getting Started

Using Harbour From a Windows Command Prompt

Getting Started With hbIDE

Basic Language Tutorial

xBase/Clipper Tutorial

The helloworld application line by line

Data Types in General (and Their Operators)

Strings

Other Considerations about the Classification of Data Types

Operators and Precedence

Boolean Algebra & Flow Control

Conditional execution

Looping

Counter-controlled Loops, and Nested Loops

& - the Macro Evaluation Operator

Arrays

Error Handling (the Clipper Way)

Functions and Procedures

Why the Main Function?

Another characteristic of variables: scope identifiers

The search for the Ludolphine

Part 1: Using the Clipper Tools (CT) Library

Part 2: Mixing C and Harbour Code

The FizzBuzz interview question: critical thinking and algorithms, with an introduction to table trace and the concept of flag

Sorting Algorithms

Grasping Recursion

Code blocks

Command Line Arguments

File Management

Working With Databases

Working with Databases

DBF Files in Other Languages

Making a first database and recording some data

A verbose way

A more concise way

Database Design Issue: the First Normal Form (1NF)

Complicating our simple database

Something More Elaborate

Workareas: more than one table at once

Testdbf.prg

Input Mask

RDDs: What Functions Are Available?

ADO RDD: Much Ado About Nothing

Case Study: Checkbook Balancing

Deleting records

An Indexed Example

Set Relation - Working with more than one table

Object Oriented Programming

Object Oriented Programming

Looking at Object-Oriented Programming from a Safety Distance

Another example

Other Features (Not Present in the Old Clipper)

Other programming topics

Hash Arrays (Associative Arrays, Also Known as "Hash Tables")

Morse Code

Regular Expressions

Error Handling With “Try-Catch-Finally” Block

Multithreading

INET

PDF

How to create a DLL

Debugging

Making Up a User Interface

Text (Console) Interfaces

GUI Design

Getting A Library

HwGUI

HMG-IDE (by Roberto Lopez)

HMG-IDE (by Walter Formigoni)