Watch out for automatic type casting

I found automatic typecasting can be a bit of a gotcha. $sText = "this.is.a.test.text"; if ( $pos = strpos($sText, "test") !== FALSE) { echo substr($sText, 0, $pos)."<".substr($sText, $pos, strlen("test")).">".substr($sText, $pos+strlen("test")); } The code seems logical enough, and the expected result would be: this.is.a.<test>.text In fact it ends up being: t<his.>is.a.test.text The reason is $pos is typecast as TRUE, not int 10, presumably because it's in the same scope as the boolean test. Then when $pos is later used as an int it's converted from TRUE to 1. You have to bracket the $pos setting to move it into its own scope to prevent it being typecast: if ( ($pos = strpos($sText, "test")) !== FALSE) { No doubt it's mentioned somewhere in the php manual, I just never came across it. Just thought I'd highlight one of the gotchas of auto typecasting for any other simpletons like me. Cheers Arno