C++ Language/Overview
Like many programming languages, C++ uses a "variable" to name a memory location which can store some value.
A running C++ program executes an assignment statement iX=1;
to assign value 1
into variable iX
.
But first, each variable has a "type" (its way of using its memory bits to represent its values, such as int
) which must be specified by the programmer "defining" that variable within some "scope".
Assignment is only one example of a statement; a sequence of statements can be grouped into a code block (written within braces).
The execution of that code block can be conditional, depending on the result of testing a "relational expression" (e.g., the equality of two sub-expressions in if (iX + iY == 33) {block}
).
Generally, a program's execution linearly flows from first statement to last statement, but that program flow can jump around as controlled by loops or by "calling a function".
Information can be "passed" into the function (via its "parameters"), and/or returned from the function (by a return 123;
statement).
C++ enables object-oriented programming (OOP), where an "object" is an instance of a type whose data is a combination of "data members" (as had already been listed in some "class" definition). That class definition also describes "member functions", whose usage is designed to manipulate a specific instance of those data members (i.e., to manipulate a specific object).