Difference between revisions of "Var"
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{{Var}} | {{Var}} | ||
− | Var is a [[Keyword|keyword]] used to mark the section where [[Variable|variables]] and their data [[Type|type]]s are declared. When used for a parameter of a [[Procedure|procedure]] or [[Function|function]] then '''var''' indicates the use of a [[Variable parameter|variable parameter]]. | + | '''Var''' is a [[Keyword|keyword]] used to mark the section where [[Variable|variables]] and their data [[Type|type]]s are declared. When used for a parameter of a [[Procedure|procedure]] or [[Function|function]] then '''var''' indicates the use of a [[Variable parameter|variable parameter]]. |
Variables are typically declared at the beginning of a [[Program|program]], [[Procedure|procedure]], [[Function|function]] or [[Unit|unit]]. | Variables are typically declared at the beginning of a [[Program|program]], [[Procedure|procedure]], [[Function|function]] or [[Unit|unit]]. | ||
− | <syntaxhighlight>var | + | <syntaxhighlight> |
− | age: integer;</syntaxhighlight> | + | var |
+ | age: integer; | ||
+ | </syntaxhighlight> | ||
If you are planning to use various variables of the same type, they can be grouped so they share the same type definition. The variables must be separated by a [[Comma|comma]]. | If you are planning to use various variables of the same type, they can be grouped so they share the same type definition. The variables must be separated by a [[Comma|comma]]. | ||
− | <syntaxhighlight>var | + | <syntaxhighlight> |
− | FirstName, LastName, address: string;</syntaxhighlight> | + | var |
+ | FirstName, LastName, address: string; | ||
+ | </syntaxhighlight> | ||
+ | |||
+ | A '''var''' variable as a procedure or function parameter can bet used for a returnvalue: | ||
+ | <syntaxhighlight> | ||
+ | procedure foo( var v1: sometype; out v2: sometype; const v3: sometype ) | ||
+ | begin | ||
+ | v1 := v1 + v3; // input and return vlaue | ||
+ | v2 := v3; // only return value | ||
+ | v3 := myconst; // immutable... only input | ||
+ | end; | ||
+ | </syntaxhighlight> | ||
+ | |||
== See also == | == See also == |
Revision as of 14:04, 17 July 2016
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Var is a keyword used to mark the section where variables and their data types are declared. When used for a parameter of a procedure or function then var indicates the use of a variable parameter.
Variables are typically declared at the beginning of a program, procedure, function or unit.
var
age: integer;
If you are planning to use various variables of the same type, they can be grouped so they share the same type definition. The variables must be separated by a comma.
var
FirstName, LastName, address: string;
A var variable as a procedure or function parameter can bet used for a returnvalue:
procedure foo( var v1: sometype; out v2: sometype; const v3: sometype )
begin
v1 := v1 + v3; // input and return vlaue
v2 := v3; // only return value
v3 := myconst; // immutable... only input
end;