php foreach循环中使用引用时问题
文章来给大家介绍php foreach循环中使用引用问题分析与注意事项,希望此文章对各位同学会有所帮助。
例
代码如下 | 复制代码 |
$array=array('a','b','c','d'); |
在foreach循环中,当循环结束后,$key和$val变量都不会自动释放掉。值会被保留下来。
当foreach使用引用的情况下,会出现如下的情况,需要注意。
代码如下 | 复制代码 |
$array=array('a','b','c','d'); |
当$val变量使用&引用后,当执行foreach循环结束后,$val指向了和$arrar[3]相同的内存地址。
当foreach循环结束后$val变量还是存在的,所以在foreach循环结束后改变$val的值,就相当于改变了$arrar[3]的值。

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