PHP array_keys() Function
PHP Array Reference
Example
Return an array containing the keys:
<?php
$a=array("Volvo"=>"XC90","BMW"=>"X5","Toyota"=>"Highlander");
print_r(array_keys($a));
?>
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Definition and Usage
The array_keys() function returns an array containing the keys.
Syntax
array_keys(array,value,strict)
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".
|
Technical Details
Return Value: |
Returns an array containing the keys |
PHP Version: |
4+ |
Changelog: |
The strict parameter was added in PHP 5.0 |
More Examples
Example 1
Using the value parameter:
<?php
$a=array("Volvo"=>"XC90","BMW"=>"X5","Toyota"=>"Highlander");
print_r(array_keys($a,"Highlander"));
?>
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Example 2
Using the strict parameter, false:
<?php
$a=array(10,20,30,"10");
print_r(array_keys($a,"10",false));
?>
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Example 3
Using the strict parameter, true:
<?php
$a=array(10,20,30,"10");
print_r(array_keys($a,"10",true));
?>
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