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php - Checking if string contains "HTTP://"

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";

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.

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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.

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

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

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