Difference between revisions of "Function"
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A function which is part of an object is called a [[Property|property]] and can be assigned/return a value (if you can't assign a value, it would be a [[Method|method]]) | A function which is part of an object is called a [[Property|property]] and can be assigned/return a value (if you can't assign a value, it would be a [[Method|method]]) | ||
| + | |||
| + | == Function parameters == | ||
| + | |||
| + | * Call by value | ||
| + | * [[Variable parameter]] (call by reference) | ||
| + | * Out parameter | ||
| + | * Const parameter | ||
| + | * [[Default parameter]] | ||
| + | * Open array parameters | ||
| + | * Array of const | ||
== Examples == | == Examples == | ||
Revision as of 19:48, 19 February 2016
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Overview
A function is a declaration of a routine which may be invoked
- from within the unit that declares it
- from outside the unit if the function is public,
- or from within a program
The routine returns a value as part of its definition. A routine that does not return a value as part of its definition is a procedure.
A function which is part of an object is called a property and can be assigned/return a value (if you can't assign a value, it would be a method)
Function parameters
- Call by value
- Variable parameter (call by reference)
- Out parameter
- Const parameter
- Default parameter
- Open array parameters
- Array of const
Examples
Addition of two integers example:
function add(c1, c2 : integer) : integer;
begin
add := c1 + c2; //or use result := in Object Pascal/Delphi mode
end;
var
total: integer;
begin
total := add(4, 5);
writeln (total); // result is 9
end.