实验1php
var_dump(memory_get_usage()); $a = 'test'; var_dump(memory_get_usage()); $b = & $a; var_dump(memory_get_usage()); $a = ''; var_dump(memory_get_usage()); $b = ''; var_dump(memory_get_usage());
输出函数
int(2503368) int(2503400) int(2503400) int(2503400) int(2503400)
实验二code
var_dump(memory_get_usage()); $a = 'test'; var_dump(memory_get_usage()); $b = & $a; var_dump(memory_get_usage()); unset($a); var_dump(memory_get_usage()); unset($b); var_dump(memory_get_usage());
输出内存
int(2503344) int(2503376) int(2503376) int(2503376) int(2503344)
结论get
赋值为null不能释放内存,函数unset()只有unset全部引用的变量,当内存的引用计数为0时,内存才回被释放。class