php 5.3新引入的garbage collection

以下代码来源www.php.net

 

<?php

// Start caching variables
gc_enable ();

$value = "Hello world";

echo $value. "</ br>";

$value = "Bye world";

echo $value. "</ br>";

// Load the variables into garbage "Previous"

$previous = gc_collect_cycles();

// Get the previous value of "value" with old 0.
// 0 is the previous value, that means I take the first value "garbage" of the variable.

$value = $previous ['value'] [0]

//Get empty the garbage collection variable to disallow from the memory.
gc_disable($previous);

echo $value. "</ br>";

/*
This would return:

Hello world
Bye world
Hello world
*/
?>

 

5.3引入这个功能，可以调用已经被销毁或改变的变量，让Php更加灵活