[PHP] Making sure a variable is an integer

[Chronicle]

I know its just a simple function, can't remember or find what it is.

Need to make sure that for example ...

$id = $_GET['id']

is always ONLY an integer. I've done it but it requires 3 if statements, i'm know i had a (built in) function that worked a while ago but can't remember it.

Thanks

 

[isset]

is_numeric()

 

[Immsy]

http://uk.php.net/manual/en/function.is-integer.php

 

[Beansprout]

You can't use is_int() because GET/POST input is always a string, but you can use this, shamefully nicked from the is_numeric() comments:

function is_whole_number($var){
  return (is_numeric($var)&&(intval($var)==floatval($var)));
}

 

[Dj_Jestar]

or:

<?php

if (strval(intval($_GET['val'])) === $_GET['val']) {
    //$val is an integer value.
}

?>

 

[Chronicle]

Is there a way to just convert any string/floating point number, into just an integer?

ie, something like $id = MakeItIntoAnInt($_GET['id']) ?

Thanks

 

[Beansprout]

http://www.php.net/intval

 

[Dfhaii]

You can cast it ie

$four = '4'; //string
$four = (int) $four; // should be an int, let's check
var_dump($four); //prints int(4), job's a good'un

Col

 

[Dj_Jestar]

In a sloppy fashion (imo):

<?php

$number = '5';
$number+0;

//$number is now an int

?>

intval() or typecasting (when used in a particular context) is the least sloppy.

<?php

function ReturnInt ($val)
{
    return (int) (($val / ($val - 5)) * 8);
}

?>

 

[Chronicle]

Thanks for your replies.

This is something I've never worked out with PHP... In Java or whatever, you always define if something is for example a string, int etc. How do you do this sort of thing in PHP?

When i set $example = "1", would that, like that, be a string? Or an integer?

Thanks

 

[Pine]

When i set $example = "1", would that, like that, be a string? Or an integer?

String, because it's surrounded in quotes. $example = 1 on the other hand would be an interger.

 

[Inquisitor]

This is something I've never worked out with PHP... In Java or whatever, you always define if something is for example a string, int etc. How do you do this sort of thing in PHP?

You don't. PHP, unlike C#, Java et al, is not a strongly-typed language, so any variable can be of any type (and can change).

 

[Chronicle]

ah right. Thanks. Never knew that lol

 

[robmiller]

Thanks for your replies.

This is something I've never worked out with PHP... In Java or whatever, you always define if something is for example a string, int etc. How do you do this sort of thing in PHP?

When i set $example = "1", would that, like that, be a string? Or an integer?

Thanks

PHP just performs implicit type conversions when you need it to.

$int = 4;
$string = "5";

// casts the string to an int in order to compare the two:
var_dump($string > $int); // bool(true);