gettype

(PHP 4, PHP 5)

gettypeResituisce il tipo di una variabile

Descrizione

string gettype ( mixed $var )

Restituisce il tipo della variabile PHP var.

Avviso

Non utilizzare gettype() per testare certi tipi di variabili poiché la stringa restistuita potrebbe variare nelle versioni future. Inoltre questa funzione è lenta dato che richiede confronti tra stringhe

Piuttosto utilizzare le funzioni is_*.

La stringa restituita può assumere i seguenti valori:

  • "boolean" (dalla versione 4 di PHP)
  • "integer"
  • "double" (per ragioni storiche viene restituito "double" in caso di variabile di tipo float, e non semplicemente "float")
  • "string"
  • "array"
  • "object"
  • "resource" (dalla versione 4 di PHP)
  • "NULL" (dalla versione 4 di PHP)
  • "user function" (soltanto in PHP 3, deprecated)
  • "unknown type"

Nella versione 4 di PHP si dovrebbe applicare alle funzioni function_exists() o method_exists() al posto del precedente gettype().

Vedere anche settype(), is_array(), is_bool(), is_float(), is_int(), is_null(), is_numeric(), is_object(), is_resource(), is_scalar() e is_string().

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User Contributed Notes 11 notes

up
5
gilthansNOSPAM at gmail dot com
8 years ago
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
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3
langpavel at phpskelet dot org
3 years ago
This function returns string representation of type. This is generalization of get_class(). I try to order is_* tests by density of occurence, but is bad idea to use result of this call in conditions for performance reasons, usefull and better than gettype for debugging messages.
Note, that last line should not be never executed.
Also has no sense to make input parameter optional.

<?php
function get_type($var)
{
    if(
is_object($var))
        return
get_class($var);
    if(
is_null($var))
        return
'null';
    if(
is_string($var))
        return
'string';
    if(
is_array($var))
        return
'array';
    if(
is_int($var))
        return
'integer';
    if(
is_bool($var))
        return
'boolean';
    if(
is_float($var))
        return
'float';
    if(
is_resource($var))
        return
'resource';
   
//throw new NotImplementedException();
   
return 'unknown';
}
?>
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3
Wilson212
3 years ago
I did some benchmarking and your method here is alot slower then using the actual gettype(); (Using php 5.3.4)
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3
PPKu-N0-SPAM-schy at mediasoft-berlin dot de
3 years ago
After some testing I found a bug in my function "myGetType":
The check for "is_callable" was done before "is_string", so that something like <?php echo myGetType("max"); ?> would output: "function reference" instead of "string"

"is_callable" and "is_string" can't be checked together in this method, so I've removed the check for is_callable because it's a very rare usage case and if it's a valid string the check for is_callable never executes because is_string would be reached first (or vice-versa).

So here is the new function without "is_callable"-Check:
<?php
   
/**
     * Returns the type of the var passed.
     *
     * @param mixed $var Variable
     * @return string Type of variable
     */
   
function myGetType($var)
    {
        if (
is_array($var)) return "array";
        if (
is_bool($var)) return "boolean";
        if (
is_float($var)) return "float";
        if (
is_int($var)) return "integer";
        if (
is_null($var)) return "NULL";
        if (
is_numeric($var)) return "numeric";
        if (
is_object($var)) return "object";
        if (
is_resource($var)) return "resource";
        if (
is_string($var)) return "string";
        return
"unknown type";
    }
?>
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2
SoN9ne at gmail dot com
4 years ago
This is my work around for the gettype warning. Hope some find it useful.

<?php
   
/**
     * Returns the type of the passed var
     * - PHP warns against using gettype(), this is my workaround
     *
     * @param mixed $var
     * @return string
     */
   
function myGetType($var)
    {
        if (
is_array($var)) return "array";
        if (
is_bool($var)) return "boolean";
        if (
is_callable($var)) return "function reference";
        if (
is_float($var)) return "float";
        if (
is_int($var)) return "integer";
        if (
is_null($var)) return "NULL";
        if (
is_numeric($var)) return "numeric";
        if (
is_object($var)) return "object";
        if (
is_resource($var)) return "resource";
        if (
is_string($var)) return "string";
        return
"unknown type";
    }
?>

[EDITOR thiago NOTE: Code has been updated by PPKu-N0-SPAM-schy at mediasoft-berlin dot de]
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2
matt at appstate
9 years ago
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.

<?php
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
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0
wojciech dot fornal at gmail dot com
25 days ago
@langpavel at phpskelet dot org

Doesn't the gettype return the string already? Using get_class seems to be the only "useful" part of that solution. All that can be reduced to somewhere half in terms of the amount of code.
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0
sneskid at hotmail dot com
7 years ago
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
?>
up
-1
skatebiker at hotmail dot com
6 years ago
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
}
?>
up
-1
andrey at php dot net
7 years ago
The function returns "unicode" for Unicode strings in PHP6.
up
-2
Crysis nerd
3 years ago
I wanted to compare the type of 2 vars.
1st method: Use this Funktion (gettype) and compare with ==
2nd method: Compare every type per is_[type]
Here a little Benchmark:
(I had to break line twice..)

<?php
$var1
= "Hallo";
$var2 = "Käsekuchen";
$var3 = 3.141526;
$Start = microtime(true);
for(
$i=0;$i<10000;$i++)
{
if(
is_bool($var1)&&is_bool($var2)||is_int($var1)&&
is_int($var2)||is_string($var1)&&is_string($var2)||
is_object($var1)&&is_object($var2)||is_array($var1)
&&
is_array($var2))
    {
       
//same
   
}
    if(
is_bool($var3)&&is_bool($var2)||is_int($var3)&&
is_int($var2)||is_string($var3)&&is_string($var2)||
is_object($var3)&&is_object($var2)||is_array($var3)
&&
is_array($var2))
    {
       
//same
   
}
}
$time = microtime(true)-$Start;
echo
"Zeit fuer if abfrage:  ".$time."<br>";

$Start = microtime(true);
for(
$i=0;$i<10000;$i++)
{
    if(
gettype($var1)==gettype($var2))
    {
       
//same
   
}
    if(
gettype($var3)==gettype($var2))
    {
       
//same
   
}
}
$time = microtime(true)-$Start;
echo
"Zeit fuer funktion  :  ".$time;
?>

Output:
Zeit fuer if abfrage: 0.0257611274719
Zeit fuer funktion : 0.0139331817627

So the function isnt so slow...

Lukas
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