PHP的错误条件 [英] php false place in condition

问题描述

通常将false与false进行比较，其中false在右侧:

Usually comparing with false is done like this where false is on right side:

if(strpos($str, 'php') !== false) {
    // code
}

但是我也注意到左侧的各个地方false

But I have also noticed at various places false on left side:

if(false !== strpos($str, 'php')) {
    // code
}

据我了解，它们是一样的，为什么有些人将false放在左侧?有什么特别的东西，我想念的吗?

As far as I understand, they are same then why some people put false on left side? Is there anything special about it, something I am missing ?

推荐答案

那是开发人员发明的不专心的

Thats something inattentive developers invented

问题"

if ($var = false) { /* code */ }

解决方案

if (false = $var) { /* code */ }

最后一个失败，因此开发人员发现他错过了另外一个=，!，...在这里

Latter one will fail and thus the developer sees, that he misses an additional =, !, ... here

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