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
?>
gettype
(PHP 4, PHP 5)
gettype — 変数の型を取得する
説明
string gettype ( mixed $var )PHP 変数 var の型を返します。
警告
返された文字列は将来のバージョンで変更される可能性があるので、 gettype() を使用して型を調べることはしないでください。 更に、この関数は文字列比較を行うため、処理が遅くなります。
代わりに is_* 関数を使用してください。
返り値
返された文字列は、以下のいずれかの値を持ちます。
PHP 4 の場合、ある関数に関する gettype() の以前の使用法を置き換えるには、function_exists() および method_exists() を使用する必要があります。
参考
| settype() |
| is_array() |
| is_bool() |
| is_float() |
| is_int() |
| is_null() |
| is_numeric() |
| is_object() |
| is_resource() |
| is_scalar() |
| is_string() |
gettype
sneskid at hotmail dot com
06-Mar-2007 06:56
06-Mar-2007 06:56
gilthansNOSPAM at gmail dot com
12-Sep-2005 05:18
12-Sep-2005 05:18
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($number4);
?>
This will return:
-1.#IND
1
boolean
double
integer
boolean
0
1
1
0
PHP Warning: Division by zero in C\test.php on line 2 PHP Warning: Division by zero in C:\test.php on line 5
matt at appstate
17-Dec-2004 04:10
17-Dec-2004 04:10
Here is something that had me stumped with regards to gettype and is_object.
Gettype will report an incomplete object as such, whereas is_object will return FALSE.
if (!is_object($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
jose at vocis dot com
15-Sep-2000 01:22
15-Sep-2000 01:22
Also returns "NULL" for variables assigned the return of a function that returned no value via "return;".
<code>
function weird(){
return;
}
$a=weird();
</code>
isset($a) <> 1
empty($a) <> 1
gettype($a) == NULL
-Jose Batista
ojones at dotclick dot com
01-Sep-2000 02:19
01-Sep-2000 02:19
After calling OCIResult to retrieve a NULL result from an Oracle result-set, gettype returns the string 'NULL'.