Last updated: Wed, 22 Jul 2009

gettype

(PHP 4, PHP 5)

gettype — Verkrijg het type van een variabele

Beschrijving

string gettype ( mixed $var )

Geeft het type van de PHP variabele var terug.

Warning

Gebruik gettype() nooit om te kijken of een variabel van een bepaald type is, omdat de string die teruggeven wordt kan veranderen in nieuwere versies. Ook is dit te langzaam omdat het door middel van string-vergelijking werkt.

In plaats hiervan moet je de is_* functies gebruiken.

Moggelijke waarden voor de teruggeven string zijn:

"boolean" (vanaf PHP 4)
"integer"
"double" (om historische redenen wordt "double" teruggeven als het een float betreft, en niet "float")
"string"
"array"
"object"
"resource" (vanaf PHP 4)
"NULL" (vanaf PHP 4)
"user function" (alleen in PHP 3, afgeraden)
"unknown type"

In PHP 4 moet je function_exists() en method_exists() gebruiken in plaats van het vroegere gebruik van gettype() op een functie.

Zie ook: settype(), is_array(), is_bool(), is_float(), is_integer(), is_null(), is_numeric(), is_object(), is_resource(), is_scalar(), en is_string().

import_request_variables

get_resource_type

Last updated: Wed, 22 Jul 2009

add a note User Contributed Notes
gettype

skatebiker at hotmail dot com
22-Feb-2008 02:51


In some rare cases a class instance object returns false when an object but gettype() returns "object".





<?php


$x = new classvar();





$save = serialize($x);





// ......





$obj = unserialize($save);


// here sometimes is_object() returns FALSE


if (is_object($x) || gettype($x) === "object")


{


   // ... do something


}


?>

andrey at php dot net
17-Jul-2007 07:08


The function returns "unicode" for Unicode strings in PHP6.

sneskid at hotmail dot com
05-Mar-2007 10:56


I wrote my own gettype function by just using the default is_? functions, but it took twice as long as gettype... So I decided to use gettype with a twist.



Taking the warnings about gettype to heart, and depending on your custom needs, it's worthwhile to dynamically test the gettype result with a known variable, and link the result to a predefined result. Like so:



<?php

/*

 dynamically create an array by using known variable types

 link with a predefined value

*/

$R=array();

$R[gettype(.0)]='number';

$R[gettype(0)]='number';

$R[gettype(true)]='boolean';

$R[gettype('')]='string';

$R[gettype(null)]='null';

$R[gettype(array())]='array';

$R[gettype(new stdClass())]='object';



// what is

function wis_($v){

    global $R;

    return $R[gettype($v)];

}



echo wis_('hello') . '<br/>'; // "string"

echo wis_(24) . '<br/>'; // "number"

echo wis_(0.24) . '<br/>'; // "number"

echo wis_(null) . '<br/>'; // "null"

echo wis_($R) . '<br/>'; // "array"

?>

You won't need to worry about changes in gettype's return strings in future versions.

If the result evaluates to false then you know the variable tested is some "other" type.



I also find these useful

<?php

function is_num($v){return (is_int($v) || is_double($v));}

function is_box($v){return (is_array($v)||is_object($v));}



echo is_num(null) . '<br/>'; // false

echo is_num(false) . '<br/>'; // false

echo is_num('123') . '<br/>'; // false

echo is_num(123) . '<br/>'; // true

echo is_num(123.0) . '<br/>'; // true

?>

gilthansNOSPAM at gmail dot com
11-Sep-2005 10:18


NaN and #IND will return double or float on gettype, while some inexistent values, like division by zero, will return as a boolean FALSE. 0 by the 0th potency returns 1, even though it is mathematically indetermined.



<?php

$number = 5/0;

$number2 = sqrt(-3);

$number3 = pow(0, 0);

$number4 = 0/0;



echo $number."<br />";

echo $number2."<br />";

echo $number3."<br />";

echo $number4."<br />";

echo "<br />";

echo gettype($number)."<br />";

echo gettype($number2)."<br />";

echo gettype($number3)."<br />";

echo gettype($number4);

?>



This will return:



-1.#IND

1



boolean

double

integer

boolean



0

1

1

0

PHP Warning: Division by zero in C\test.php on line 2 PHP Warning: Division by zero in C:\test.php on line 5

matt at appstate
16-Dec-2004 08:10


Here is something that had me stumped with regards to gettype and is_object.

Gettype will report an incomplete object as such, whereas is_object will return FALSE.



if (!is_object($incomplete_obj)) {

   echo 'This variable is not an object, it is a/an ' . gettype($incomplete_obj);

}



Will print:

This variable is not an object, it is a/an object

add a note

import_request_variables

get_resource_type

Last updated: Wed, 22 Jul 2009