C# Programming/Keywords/if

The if keyword identifies an if statement with the following syntax:

if-statement ::= "if" "(" condition ")" if-body ["else" else-body]

condition ::= boolean-expression

if-body ::= statement-or-statement-block

else-body ::= statement-or-statement-block

If the condition evaluates to true, the if-body executes. Curly braces ("{" and "}") allow the if-body to contain more than one statement. Optionally, an else clause can immediately follow the if-body, providing code to execute when the condition is false. Making the else-body another if statement creates the common cascade of if, else if, else if, else if, else statements:

using System;

public class IfStatementSample
{
    public void IfMyNumberIs()
    {
        int myNumber = 5;
        if (myNumber == 4)
            Console.WriteLine("This will not be shown because myNumber is not 4.");
        else if(myNumber < 0)
        {
            Console.WriteLine("This will not be shown because myNumber is not negative.");
        }
        else if(myNumber%2 == 0)
            Console.WriteLine("This will not be shown because myNumber is not even.");
        else
        {
            Console.WriteLine("myNumber does not match the coded conditions, so this sentence will be shown!");
        }
    }
}

The boolean expression used in an if statement typically contains one or more of the following operators:

Operator	Meaning	Operator	Meaning
<	less than	>	greater than
==	equal to	!=	not equal to
<=	less than or equal to	>=	greater than or equal to
&&	and	||	or
!	not

See also else.

C# Keywords
abstract as base bool break byte case catch char checked class const continue decimal default delegate do double else enum event explicit extern false finally fixed float for foreach goto if implicit in int interface internal is lock long namespace new null object operator out override params private protected public readonly ref return sbyte sealed short sizeof stackalloc static string struct switch this throw true try typeof uint ulong unchecked unsafe ushort using var virtual void volatile while
Special C# Identifiers (Contextual Keywords)
add alias async await dynamic get global nameof partial remove set value when where yield
Contextual Keywords (Used in Queries)
ascending by descending equals from group in into join let on orderby select where