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";
}
?>
gettype
(PHP 4, PHP 5, PHP 7, PHP 8)
gettype — 获取变量的类型
参数
-
value -
要检查类型的变量。
返回值
返回字符串，可能值为：
-
"boolean" -
"integer" -
"double"（由于历史原因，如果是浮点型，则返回"double"，而不仅仅是"float"） -
"string" -
"array" -
"object" -
"resource" -
"resource (closed)"自 PHP 7.2.0 起 -
"NULL" -
"unknown type"
范例
示例 #1 gettype() 示例
<?php
$data = array(1, 1., NULL, new stdClass, 'foo');
foreach ($data as $value) {
echo gettype($value), "\n";
}
?>
以上例程的输出类似于：
integer double NULL object string
更新日志
| 版本 | 说明 |
|---|---|
| 7.2.0 |
现在，已关闭的资源报告为 'resource (closed)'。
此前，已关闭的资源报告为 'unknown type'。
|
参见
- settype() - 设置变量的类型
- get_class() - 返回对象的类名
- is_array() - 检测变量是否是数组
- is_bool() - 检测变量是否是布尔值
- is_callable() - 检测参数是否为合法的可调用结构
- is_float() - 检测变量是否是浮点型
- is_int() - 检测变量是否是整数
- is_null() - 检测变量是否为 null
- is_numeric() - 检测变量是否为数字或数字字符串
- is_object() - 检测变量是否是一个对象
- is_resource() - 检测变量是否为资源类型
- is_scalar() - 检测变量是否是一个标量
- is_string() - 检测变量是否是字符串
- function_exists() - 如果给定的函数已经被定义就返回 true
- method_exists() - 检查类的方法是否存在
add a note
User Contributed Notes 11 notes
PPKu-N0-SPAM-schy at mediasoft-berlin dot de ¶
13 years ago
gilthansNOSPAM at gmail dot com ¶
18 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($number4);
?>
This will return:
-1.#IND
1
boolean
double
integer
boolean
0
1
1
0
PHP Warning: Division by zero in C\test.php on line 2 PHP Warning: Division by zero in C:\test.php on line 5
langpavel at phpskelet dot org ¶
12 years ago
This function returns string representation of type. This is generalization of get_class(). I try to order is_* tests by density of occurence, but is bad idea to use result of this call in conditions for performance reasons, usefull and better than gettype for debugging messages.
Note, that last line should not be never executed.
Also has no sense to make input parameter optional.
<?php
function get_type($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';
}
?>
SoN9ne at gmail dot com ¶
13 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]
Wilson212 ¶
12 years ago
I did some benchmarking and your method here is alot slower then using the actual gettype(); (Using php 5.3.4)
matt at appstate ¶
19 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
wojciech dot fornal at gmail dot com ¶
9 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.
samokspv1 at gmail dot com ¶
5 years ago
Result from this post http://php.net/manual/en/function.gettype.php#56662 for new PHP 7.2.10:
<?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:
INF
NAN
1
NAN
double
double
integer
double
skatebiker at hotmail dot com ¶
16 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
}
?>
sneskid at hotmail dot com ¶
17 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($v));}
echo is_num(null) . '<br/>'; // false
echo is_num(false) . '<br/>'; // false
echo is_num('123') . '<br/>'; // false
echo is_num(123) . '<br/>'; // true
echo is_num(123.0) . '<br/>'; // true
?>
ddr-2kpp (at) web dot de ¶
9 years ago
Hi there,
this fastest solution I found to identify a variable type without using gettype function:
<?PHP
function typeof($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
