php[world] 2018 - Call for Speakers

gettype

(PHP 4, PHP 5, PHP 7)

gettype변수의 자료형을 얻습니다

설명

string gettype ( mixed $var )

PHP 변수 var의 자료형을 반환합니다.

Warning

gettype()을 어떤 자료형인지 시험하기 위해 사용하지 마십시오. 반환 문자열은 앞으로 나올 버전에서 바뀔 수 있습니다. 또한, 문자열 비교를 수행하기 때문에 느립니다.

대신, is_* 함수를 사용하십시오.

인수

var

자료형을 확인할 변수

반환값

반환 문자열의 가능한 값은:

예제

Example #1 gettype() 예제

<?php

$data 
= array(11.NULL, new stdClass'foo');

foreach (
$data as $value) {
    echo 
gettype($value), "\n";
}

?>

위 예제의 출력 예시:

integer
double
NULL
object
string

참고

  • settype() - 변수의 자료형을 설정
  • is_array() - 변수가 배열인지 확인
  • is_bool() - 변수가 논리형인지 확인
  • is_float() - 변수의 자료형이 소수인지 확인합니다
  • is_int() - 변수의 자료형이 정수인지 확인합니다
  • is_null() - 변수가 NULL인지 확인합니다
  • is_numeric() - 변수가 수나 수 문자열인지 확인합니다
  • is_object() - 변수가 객체인지 확인합니다
  • is_resource() - 변수가 자원인지 확인
  • is_scalar() - 변수가 스칼라인지 확인
  • is_string() - 변수의 자료형이 문자열인지 확인합니다
  • function_exists() - Return TRUE if the given function has been defined
  • method_exists() - 클래스 메쏘드가 존재하는지 확인

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User Contributed Notes 10 notes

up
6
PPKu-N0-SPAM-schy at mediasoft-berlin dot de
7 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";
    }
?>
up
1
langpavel at phpskelet dot org
7 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';
}
?>
up
1
gilthansNOSPAM at gmail dot com
12 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
up
0
matt at appstate
13 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
up
-1
sneskid at hotmail dot com
11 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
-5
SoN9ne at gmail dot com
8 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]
up
-5
Wilson212
6 years ago
I did some benchmarking and your method here is alot slower then using the actual gettype(); (Using php 5.3.4)
up
-5
skatebiker at hotmail dot com
10 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
-3
wojciech dot fornal at gmail dot com
3 years 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.
up
-10
ddr-2kpp (at) web dot de
3 years ago
Hi there,

this fastest solution I found to identify a variable type without using gettype function:
<?PHP
function typeof($var) {
  if (
is_object($var))
    return
"object";

  if (
is_resource($var))
    return
"resource";

  return ((
$var === null) ? "null" :
      (((bool)
$var === $var) ? "bool" :
       (((float)
$var === $var) ? "float" :
        (((int)
$var === $var) ? "int" :
         (((string)
$var === $var) ? "string" :
             
"unknown"
         
)
         )
        )
       )
      );
}
?>
Maybe someone has a more elegant solution to check for object and resource types...

The complete script - including several identify- and timing functions follow:
#!/usr/bin/php
<?PHP
function typeof_trinary($var) {
  if (
is_object($var))
    return
"object";

  if (
is_resource($var))
    return
"resource";

  return ((
$var === null) ? "null" :
      (((bool)
$var === $var) ? "bool" :
       (((float)
$var === $var) ? "float" :
        (((int)
$var === $var) ? "int" :
         (((string)
$var === $var) ? "string" :
             
"unknown"
         
)
         )
        )
       )
      );
   }

function
typeof_if_query($var) {
  
  if (
is_object($var))
    return
"object";

  if (
is_resource($var))
    return
"resource";
 
  if ((bool)
$var === $var)
      return
"bool";

  if ((float)
$var === $var)
    return
"float";

  if ((int)
$var === $var)
    return
"int";

  if ((string)
$var === $var)
    return
"string";

  if (
null === $var)
    return
"null";

  return
"unknown";
}

function
typeof_gettype($var) {
    return \
gettype($var);
}

$var = 100;

echo
"start@ " . \date("Y-m-d H:i:s") . "\n";
echo
"\$var = $var - gettype(\$var) = " . gettype($var) . "\n\n";
$time = -\microtime(true);

echo
"typeof_if_query(\$var) = " . typeof_if_query($var) . "\n";
$time += \microtime(true);
echo
"duration: " . \sprintf("%0.10f",$time) . "\n\n";

$time = -\microtime(true);

echo
"typeof_gettype(\$var) = " . typeof_gettype($var) . "\n";
$time += \microtime(true);
echo
"duration: " . \sprintf("%0.10f",$time) . "\n\n";

$time = -\microtime(true);

echo
"typeof_trinary(\$var) = " . typeof_trinary($var) . "\n";
$time += \microtime(true);
echo
"duration: " . \sprintf("%0.10f",$time) . "\n\n";
?>

My console output - try the script several times!:
$ ./gettype.php
start@ 2015-01-10 01:10:37
$var = 100 - gettype($var) = integer

typeof_if_query($var) = int
duration: 0.0000500679

typeof_gettype($var) = integer
duration: 0.0000309944

typeof_trinary($var) = int
duration: 0.0000240803
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