is_int and GET or POST

Question

Why does is_int always return false in the following situation?

echo $_GET[\'id\']; //3
if(is_int($_GET[\'id\']))
    echo \'int\'; //not execut         


        

Answer 1

Checking for integers using is_int($value) will return false for strings.

Casting the value -- is_int((int) $value) -- won't help because strings and floats will result in false positive.

is_numeric($value) will reject non numeric strings, but floats still pass.

But the thing is, a float cast to integer won't equal itself if it's not an integer. So I came up with something like this:

$isInt = (is_numeric($value) && (int) $value == $value);

It works fine for integers and strings ... and some floating numbers.

But unfortunately, this will not work for some float integers.

$number = pow(125, 1/3); // float(5) -- cube root of 125
var_dump((int) $number == $number); // bool(false)

But that's a whole different question.

Answer 2

Because $_GET['id'] is a string like other parts of query string. You are not converting it to integer anywhere so is_int return false.

Answer 3

Because HTTP variables are always either strings, or arrays. And the elements of arrays are always strings or arrays.

You want the is_numeric function, which will return true for "4". Either that, or cast the variable to an int $foo = (int) $_GET['id']...

Answer 4

How i fixed it:

$int_id = (int) $_GET["id"];

if((string)$int_id == $_GET["id"]) {
echo $_GET["id"];
}

Answer 5

Because $_GET is an array of strings.

To check if the get parameter contains an integer you should use is_numeric()

Answer 6

It's probably stored as a string in the $_GET, cast it to an int.