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How to use static variables in PHP functions

php中世界最好的语言
php中世界最好的语言Original
2018-03-24 11:49:033593browse

This time I will bring you PHP functionstaticHow to use variables, what are the precautions for using PHP function static variables, the following are practical cases , let’s take a look.

In PHP, in addition to the static members properties of classes, static can also be used to define static variables in functions. This makes it easy to complete function iteration.

Example 1:

<?php
function Test()
{
  $a = 0;
  echo $a;
  $a++;
}
?>

In the above example, every time the Test function is called, a is reassigned to 0, because once the function exits, the variable a is is reassigned to 0, because variable a no longer exists once this function exits. To complete the iteration, you need to write a counting function that will not lose the current count value. You need to define the variable $a as static:

<?php
function test()
{
  static $a = 0;
  echo $a;
  $a++;
}
?>

In this way, $a is only assigned the value when it is called for the first time, and then Incremented by 1 on each call and will not be overridden.

In this way, you can use this feature to iterate a specified number of times for an operation:

Example 2: (Get the result after popping 5 elements out of an array)

$arr = range(1,10,1);
function test($arr)
{
  static $count=0;
  array_pop($arr);
  $count++;
  if ($count < 5) {
    test($arr);
  }else{
    var_dump($arr);exit;
  }
}
test($arr);

Run results:

array(5) {
 [0]=>
 int(1)
 [1]=>
 int(2)
 [2]=>
 int(3)
 [3]=>
 int(4)
 [4]=>
 int(5)
}

I believe you have mastered the method after reading the case in this article. For more exciting information, please pay attention to other related articles on the php Chinese website!

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