Php static variable example

Source: Internet
Author: User
Tags php tutorial

Class test
{
Public static function (){}
Public function B (){}
}
$ Obj = new test;

Call code

Test: ();
$ Obj-> ();
$ Obj-> B ();

 

Example: an example of static variables
<? Php Tutorial

Class myobject {
Public static $ mystaticvar = 0;

Function mymethod (){
//: A limited-scope operator.
// Use the self scope instead of the $ this scope
// Because $ this indicates only the current instance of the class, and self: indicates the class itself.
Self: $ mystaticvar + = 2;
Echo self: $ mystaticvar. "<br/> ";
 }
}

$ Instance1 = new myobject ();
$ Instance1-> mymethod (); // Display 2

$ Instance2 = new myobject ();
$ Instance2-> mymethod (); // Display 4

?>

 

<? Php

Class myobject {
Public static $ myvar = 10;
}

Echo myobject: $ myvar;

// Result: 10
?>


This function is useless because $ w3sky is set to 0 and "0" is output every time you call it ". Adding $ w3sky ++ to the variable does not work because $ w3sky does not exist once you exit this function. To write a counting function that does not lose the current count value, you must define the variable $ w3sky as static:


Example of static variables

<? Php
Function test ()
   {
Static $ w3sky = 0;
Echo $ w3sky;
$ W3sky ++;
   }
?>
Now, every time you call the test () function, the value of $ w3sky is output and added with one.

View instances


<? Php
Class foo
{
Public static $ my_static = 'foo ';
Public function staticvalue (){
Return self: $ my_static;
}
}
Class bar extends foo
{
Public function foostatic (){
Return parent: $ my_static;
}
}
Print foo: $ my_static. "n ";
$ Foo = new foo ();
Print $ foo-> staticvalue (). "n ";
Print $ foo-> my_static. "n"; // undefined "property" my_static
Print $ foo: $ my_static. "n ";
$ Classname = 'foo ';
Print $ classname: $ my_static. "n"; // can be dynamically called after php 5.3.0
Print bar: $ my_static. "n ";
$ Bar = new bar ();
Print $ bar-> foostatic (). "n ";
?>
For more details, see: http://www.111cn.net/phper/php-cy/33303.htm

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