#50738 [Opn]: Unclear documentation in numerical string comparison

ID: 50738 Updated by: rquadling@php.net Reported By: I dot F dot A dot C dot Fokkema at LUMC dot nl Status: Open Bug Type: Documentation problem Operating System: All PHP Version: Irrelevant New Comment: How about ... "If you compare an integer value with a string value (as opposed to comparisons including type; === and !===), ..." Previous Comments: ------------------------------------------------------------------------ [2010-01-13 11:07:06] I dot F dot A dot C dot Fokkema at LUMC dot nl Description: ------------ Hi guys, After someone filed bug report #23110, the documentation was greatly improved to emphasize pitfalls when comparing numerical strings. However, I want to suggest an addition because in my point of view it's not clear enough. == and === compare numerical strings differently: echo (1 == "1e0") // Returns true, as documented echo (1 === "1e0") // Returns false as expected, because the types are different echo ("1" == "1e0") // Returns true, as documented echo ("1" === "1e0") // Returns false, but the documentation says otherwise The documentation at http://www.php.net/manual/en/language.operators.comparison.php currently reads: "If you compare an integer with a string, the string is converted to a number. If you compare two numerical strings, they are compared as integers. These rules also apply to the switch statement." - this was added after bug report #23110. So according to this, ("1" === "1e0") should return true; the converted numbers are equal and they're of the same type. However, it returns false because the number conversion described in the manual does not happen when using === or !==, but that is not documented. More people have issues with this, as can be seen looking through the comments on the aforementioned manual page. Thus, I would like to suggest an addition at the end: "(...) These rules also apply to the switch statement, but they do not apply when using the operators === or !==, in which case there is no type conversion used." Or a similar explanation of course. Thank you all for your great work! ------------------------------------------------------------------------ -- Edit this bug report at http://bugs.php.net/?id=50738&edit=1