PHP Convert the keys of an array into uppercase – PHP May 11, 2011 Pramod T P Leave a comment <?php $testArray=array("key1"=>"Value1","key2"=>"Value2","key3"=>"Value3"); print_r(array_change_key_case($testArray,CASE_UPPER)); //Array ( [KEY1] => Value1 [KEY2] => Value2 [KEY3] => Value3 ) ?>