Difference between revisions of "Var"
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{{Var}} | {{Var}} | ||
| − | + | The [[Keyword|keyword]] <syntaxhighlight lang="pascal" inline>var</syntaxhighlight> is used to: | |
| − | + | * start section of [[Variable|variable]] declarations, and | |
| − | + | * declare a formal parameter as penetrating mutable. | |
| − | <syntaxhighlight> | + | == Variable declaration section == |
| + | In a [[Block|block]] the word <syntaxhighlight lang="pascal" inline>var</syntaxhighlight> starts a section of one or more variable [[Declaration|declarations]]. | ||
| + | <syntaxhighlight lang="pascal" highlight="1"> | ||
var | var | ||
| − | + | age: integer; | |
| − | </syntaxhighlight> | + | </syntaxhighlight> |
| − | + | Variables bearing the same [[Type|data type]] can be grouped, by separating their respective [[Identifier|identifiers]] by a [[Comma|comma]]: | |
| − | + | <syntaxhighlight lang="pascal" highlight="2"> | |
| − | <syntaxhighlight> | ||
var | var | ||
| − | + | firstName, lastName, address: string; | |
| − | </syntaxhighlight> | + | </syntaxhighlight> |
| − | + | == Variable parameter == | |
| − | <syntaxhighlight> | + | The word <syntaxhighlight lang="pascal" inline>var</syntaxhighlight> prior a formal parameter declaration indicates that this [[Variable parameter|parameter is variable]], that means assigning values to it will affect the named parameter at the call site. |
| − | procedure | + | <syntaxhighlight lang="pascal" highlight="1"> |
| + | procedure censor(var xxx: longWord); | ||
begin | begin | ||
| − | + | if (xxx = $4655434B) or (xxx = $6675636B) then | |
| − | + | begin | |
| − | + | xxx := $2A2A2A2A; | |
| + | end; | ||
end; | end; | ||
| − | </syntaxhighlight> | + | </syntaxhighlight> |
| − | + | After invoking <syntaxhighlight lang="pascal" inline>procedure censor</syntaxhighlight> the value of the variable that was supplied at the call site (i. e. where the procedure was called) will (possibly) have changed, too. | |
== See also == | == See also == | ||
| − | * [[ | + | * [[Const|<syntaxhighlight lang="pascal" inline>const</syntaxhighlight>]] |
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Latest revision as of 22:14, 4 July 2021
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The keyword var is used to:
- start section of variable declarations, and
- declare a formal parameter as penetrating mutable.
Variable declaration section
In a block the word var starts a section of one or more variable declarations.
var
age: integer;
Variables bearing the same data type can be grouped, by separating their respective identifiers by a comma:
var
firstName, lastName, address: string;
Variable parameter
The word var prior a formal parameter declaration indicates that this parameter is variable, that means assigning values to it will affect the named parameter at the call site.
procedure censor(var xxx: longWord);
begin
if (xxx = $4655434B) or (xxx = $6675636B) then
begin
xxx := $2A2A2A2A;
end;
end;
After invoking procedure censor the value of the variable that was supplied at the call site (i. e. where the procedure was called) will (possibly) have changed, too.
