[PHP] PHP variable memory release

adopt PHP memory_get_usage() Function to get the physical memory occupied by the current process , The comparison shows that ：

1、unset() Function can free memory

2、 The local variables inside the function will be automatically released after the function is executed
Look at the code below ：

<?php
echo __LINE__ . ' ' . memory_get_usage() . "\n"; // 36640

function a () {
    $a = str_repeat("Hello", 4242);
    echo __LINE__ . ' ' . memory_get_usage() . "\n"; // 36640

    unset($a);

    echo __LINE__ . ' ' . memory_get_usage() . "\n"; // 36640
}
a();

echo __LINE__ . ' ' . memory_get_usage() . "\n"; // 36640

#unset($a);

#echo memory_get_usage() . "\n"; // 36744

result ：

2 --355056

6-- 379664

10-- 355088

14 --355088

The first column is the line number

Conclusion
It can be used in obvious places unset() Function to display the reclaimed memory , In scenarios with complex functions, memory can be reclaimed in the form of functions