Difference between revisions of "Variable parameter"

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{{Variable parameter}}
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{{MenuTranslate| page=Variable parameter}}
  
 
Variable parameter (or Reference Parameter) is input and output parameter  
 
Variable parameter (or Reference Parameter) is input and output parameter  
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== Read more ==
 
== Read more ==
  
* [[doc:/ref/refsu48.html#x120-12700011.3.2| Variable parameter]]
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* [http://lazarus-ccr.sourceforge.net/fpcdoc/ref/refsu48.html Variable parameter]
* [[Parameters/es|Parámetros]]
 
 
* [[Xor]]
 
* [[Xor]]
 
* [[If]]
 
* [[If]]

Revision as of 22:40, 18 March 2015

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Variable parameter (or Reference Parameter) is input and output parameter meaning it can be used for passing a value to a function or a procedure as well as to get back a value from function or procedure. It indicated by the use of the keyword var in front of the formal parameter.

Variable parameter given a new nickname. The method refers to the same variable and changes made will affect the actual variable.


XOR swap

  procedure XorSwap(  var i,j:integer );
  begin
    i := i xor j ;
    j := i xor j ;
    i := i xor j ;
  end;

OrderSmallBig

  procedure OrderSmallBig( var a,b:integer );
  begin
    if a > b then XorSwap( a, b );
  end;

Read more