PHP strtolower() & strtoupper() Functions

strtolower(string) — This PHP function returns a string with all the alphabetic characters in the input string converted to lowercase.

strtoupper(string) — This PHP function returns a string with all the alphabetic characters in the input string converted to uppercase.

Try it here. Enter your string below to see the function in action:
e.g. An input of 'My had a little lamb.' will produce
'my had a little lamb.' for strtolower() and
'MY HAD A LITTLE LAMB.' for strtoupper().


Function Results
Test String:
strtolower() Resulting String:
strtoupper() Resulting String: