| Description |
The Var keyword is used to start a section of variable definitions.
The section is terminated by the next keyword in a program.
Within the section, one or more variables may be defined. These can be of any data type.
1.Variables with no initial value
These are defined with a given type, such as string or Integer but with no assigned default initial value.
2.Variables with an initial value
These are defined with a given type, such as string or Integer with an assigned initial value. Only global variables may be initialised.
3.Variable routine parameters
When passing data to a routine (function or procedure), you can prefix the parameter definition with Var if the variable itself is to be updated by the routine. This allows a caller to pass data to a routine that will be enriched by the routine.
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| Related commands |
| Const |
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Starts the definition of fixed data values |
| Function |
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Defines a subroutine that returns a value |
| Out |
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Identifies a routine parameter for output only |
| Procedure |
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Defines a subroutine that does not return a value |
| Type |
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Defines a new category of variable or process |
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| Example code : Defining local and parameter variables |
Var // Local variables
apples, bananas : Integer;
begin
// Initialise our fruit counts
apples := 1;
bananas := 1;
// Show their initial values
WriteLn('Apples = '+IntToStr(apples));
WriteLn('Bananas = '+IntToStr(bananas));
WriteLn('');
// Increment them in the UpdateCounts routine
UpdateCounts(apples, bananas);
// Show their new values - only Bananas will be updated
WriteLn('Apples = '+IntToStr(apples));
WriteLn('Bananas = '+IntToStr(bananas));
end;
// A procedure to increment the passed parameter values
procedure TForm1.UpdateCounts(count1: Integer; Var count2: Integer);
begin
// Increment both passed parameter values
Inc(count1);
Inc(count2);
end;
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| Show full unit code |
Apples = 1
Bananas = 1
Apples = 1
Bananas = 2
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