Is it safe to vì something like the following?
if ($password === $password2) ... 
The reason to lớn use it is because strcmp
returns 0 if str1 is greater than str2, & 0 if they are equal.Bạn sẽ xem: How to compare strings in php
=== only returns true or false, it doesn"t tell you which is the "greater" string.
Bạn đang xem: String function
You should never use == for string comparison. === is OK.
$something = 0;echo ("password123" == $something) ? "true" : "false";Just run the above code and you"ll see why.
$something = 0;echo ("password123" === $something) ? "true" : "false";Now, that"s a little better.
Don"t use == in PHP. It will not vì what you expect. Even if you are comparing strings lớn strings, PHP will implicitly cast them lớn floats và do a numerical comparison if they appear numerical.
For example "1e3" == "1000" returns true. You should use === instead.
Well..according khổng lồ this php bug report , you can even get 0wned.It gives you a warning , but still bypass the comparison.You should be doing === as Always remember, when comparing strings, you should use === operator (strict comparison) & not == operator (loose comparison).
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Summing up all answers :== is a bad idea for string comparisons.It will give you "surprising" results in many cases. Don"t trust it.
strcmp() should be used if you need lớn determine which string is "greater", typically for sorting operations.
Using == might be dangerous.Note, that it would cast the variable to lớn another data type if the two differs.
Examples:
echo (1 == "1") ? "true" : "false";echo (1 == true) ? "true" : "false";As you can see, these two are from different types, but the result is true, which might not be what your code will expect.
Using ===, however, is recommended as chạy thử shows that it"s a bit faster than strcmp() and its case-insensitive alternative strcasecmp().
Quick googling yells this speed comparison: http://snipplr.com/view/758/
strcmp() & === are both case sensitive but === is much fastersample code: http://snipplr.com/view/758/
strcmp will return different values based on the environment it is running(Linux/Windows)!The reason is the that it has a bug as the bug report says https://bugs.php.net/bug.php?id=53999
Please handle with care!!Thank you.
You can use strcmp() if you wish lớn order/compare strings lexicographically. If you just wish to check for equality then == is just fine. Also The function can help in sorting. To be more clear about sorting. Strcmp() returns less than 0 if string1 sorts before string2, greater than 0 if string2 sorts before string1 or 0 if they are the same. For example$first_string = "aabo";$second_string = "aaao";echo $n = strcmp($first_string,$second_string);The function will return greater than zero, as aaao is sorting before aabo.
