检查字符串是否包含"HTTP://" [英] Checking if string contains "HTTP://"

问题描述

我想知道为什么这段代码不起作用:

I am wondering why this code is not working:

// check to see if string contains "HTTP://" in front

if(strpos($URL, "http://")) $URL = $URL;
else $URL = "http://$URL";

如果确实发现该字符串不包含"HTTP://"，则如果最后一个字符串包含"http://"，则最终字符串为"HTTP://HTTP://foo.foo".

If it does find that the string doesn't contain "HTTP://" the final string is "HTTP://HTTP://foo.foo" if it contiains "http://" in front.

推荐答案

因为该字符串的返回值为0，该字符串的计算结果为false.字符串是零索引的，因此，如果在字符串的开头找到http://，则该位置为0，而不是1.

Because it's returning 0 for that string, which evaluates to false. Strings are zero-indexed and as such if http:// is found at the beginning of the string, the position is 0, not 1.

您需要使用!==将其用于严格的不等式与boolean false进行比较:

You need to compare it for strict inequality to boolean false using !==:

if(strpos($URL, "http://") !== false)

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