PHP/Language Basics/Variable Scope

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Defining Variable Scope

   <source lang="html4strict">

<?php $a = 7; function test() { 

 $a = 20;

} test(); echo "\$a = $a\n"; ?> 

 </source>


local variables

   <source lang="html4strict">

<?php $x = 4; function assignx () { 

  $x = 0;
  print "\ $x inside function is $x. 
";

} assignx(); print "\ $x outside of function is $x.
";

?> 

 </source>


More Working with Variable Scope

   <source lang="html4strict">

<?php 

   function getglobal() {
       global $my_global;
       echo "The value of \$foobar is "$foobar"
";
   }
   $my_global = 20;
   getglobal();

?> 

 </source>


Scope of a Variable

   <source lang="html4strict">

<?php 

 $a = "asdf";
 function music (){
     $a = "Music is great";
 }
 print $a;

?> 

      </source>


Use variable defined outside function

   <source lang="html4strict">

<?php 

 $ilike = "Rock";
 function music(){
     echo "I love listening to $ilike music!", "\n";
 }
 music();

?> 

      </source>


Variable Scope

   <source lang="html4strict">

<?php 

 $num;
 function make_triple($arg)
 {
   global $num;
   $num = $arg + $arg +$arg;
   thrice();
 }
 function thrice()
 {
   global $num;
   echo("The value is $num");
 }

?> <html> 

<head>
 <title>Variable Scope</title>
</head>
<body>

<?php make_triple(4); ?>

</body>

</html> 

 </source>


Variable Scope: A Variable Declared Within a Function Is Unavailable Outside the Function

   <source lang="html4strict">

<html> <head> <title>Local Variable Unavailable Outside a Function</title> </head> <body>

<?php 

   function test() {
      $testvariable = "this is a test variable";
   }
   print "test variable: $testvariable
";

?>

</body> </html> 

 </source>


Variable scope: function

   <source lang="html4strict">

<?php 

 increment ();
 increment ();
 increment ();
 function increment () {
     $a=0;
     echo $a;
     $a++;
 }

?> 

      </source>


Variable Scope in Functions

   <source lang="html4strict">

function foo( ) { 

           $bar = "wombat";
   }
   $bar = "baz";
   foo( );
   print $bar;
 
 </source>


Variables Defined Outside Functions Are Inaccessible from Within a Function by Default

   <source lang="html4strict">


<html> <head> <title>Variables Defined Outside Functions Are Inaccessible from Within a Function by Default</title> </head> <body> <?php $life = 42; function meaningOfLife(){ 

    print "The meaning of life is $life
";

} meaningOfLife(); ?> </body> </html> 

      </source>
Источник — «http://wbex.ru/index.php?title=PHP/Language_Basics/Variable_Scope&oldid=887»