PHP | array_change_key_case() Function
Last Updated :
08 Jan, 2018
The array_change_key_case() function is an inbuilt function in PHP and is used to change case of all of the keys in a given array either to lower case or upper case.
Syntax:
array array_change_key_case(in_array, convert_case)
Parameters: This function accepts two parameters out of which one is mandatory and the other is optional. The two parameters are described below:
- in_array (mandatory): This parameter refers to the array whose key’s case is needed to be changed.
- convert_case (optional): This is an optional parameter and refers to the ‘case’ in which we need to convert the keys of the array. This can take two values, either CASE_UPPER or CASE_LOWER. CASE_UPPER value determines the uppercase and CASE_LOWER determines lowercase. If the convert_case parameter is not passed then it’s default value is taken which is CASE_LOWER.
Note: If the second parameter is ignored then by default the keys of array will get converted to lowercase.
Return Type: The function returns an array with the changed case of the key, either to lowercase or to upper case.
Let us now look at some programs to get a better understanding of working of array_change_key_case() function.
-
Below program converts the case of keys to uppercase:
<?php
function change_case( $in_array ){
return ( array_change_key_case ( $in_array , CASE_UPPER));
}
$array = array ( "Aakash" => 90, "RagHav" => 80,
"SiTa" => 95, "rohan" => 85, "RISHAV" => 70);
print_r(change_case( $array ));
?>
|
Output:
Array
(
[AAKASH] => 90
[RAGHAV] => 80
[SITA] => 95
[ROHAN] => 85
[RISHAV] => 70
)
-
If we ignore the second parameter convert_case in the function array_change_key_case() then the keys will be converted to lowercase. Below program illustrates this:
<?php
function change_case( $in_array ){
return ( array_change_key_case ( $in_array ));
}
$array = array ( "Aakash" => 90, "RagHav" => 80,
"SiTa" => 95, "rohan" => 85, "RISHAV" => 70);
print_r(change_case( $array ));
?>
|
Output:
Array
(
[aakash] => 90
[raghav] => 80
[sita] => 95
[rohan] => 85
[rishav] => 70
)
-
If we don’t pass an array to the function then PHP_Warning is popped up, but the program works and No Output is generated. Below program illustrates this
<?php
function change_case( $in_array ){
return ( array_change_key_case ());
}
$array = array ( "Aakash" => 90, "RagHav" => 80,
"SiTa" => 95, "rohan" => 85, "RISHAV" => 70);
print_r(change_case( $array ));
?>
|
Output:
No Output
Warning:
PHP Warning: array_change_key_case() expects at least 1 parameter,
0 given in /home/7d540b2d77cbbfa46af4fb8798fb5e79.php on line 5
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