PHP array_keys() Function
 Complete PHP Array Reference
Definition and Usage
The array_keys() function returns an array containing the keys.
Syntax
| Parameter |
Description |
| array |
Required. Specifies an array |
| value |
Optional. You can specify a value, then only the keys with this value are returned |
| strict |
Optional. Used with the value parameter. Possible values:
- true - Returns the keys with the specified value, depending on type: the number
5 is not the same as the string "5".
- false - Default value. Not depending on type, the number 5 is the same as the string "5".
|
Example 1
<?php
$a=array("a"=>"Horse","b"=>"Cat","c"=>"Dog");
print_r(array_keys($a));
?>
|
The output of the code above will be:
Array ( [0] => a [1] => b [2] => c )
|
Example 2
Using the value parameter.
<?php
$a=array("a"=>"Horse","b"=>"Cat","c"=>"Dog");
print_r(array_keys($a,"Dog"));
?>
|
The output of the code above will be:
Example 3
Using the strict parameter: false
<?php
$a=array(10,20,30,"10");
print_r(array_keys($a,"10",false));
?>
|
The output of the code above will be:
Array ( [0] => 0 [1] => 3 )
|
Example 4
Using the strict parameter: true
<?php
$a=array(10,20,30,"10");
print_r(array_keys($a,"10",true));
?>
|
The output of the code above will be:
Complete PHP Array Reference
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