PHP array_change_key_case() Function
The array_change_key_case() function returns an array with all the keys converted from the lower or upper case. It returns FALSE if it is not an array.
Syntax
Parameters:
- array (mandatory): The first parameter is an array whose keys are subject to change to lower or upper.
- convert_case (optional): It is an optional parameter that takes CASE_UPPER or CASE_LOWER, the case in which you want to convert. The parameter's default value is CASE_LOWER, in case no value is passed.
Return Type: The function returns an array with lower or upper case keys.