Swap Upper and Lower Case Characters in a String

You are given a string containing both upper case and lower case characters as an argument. Swap the casing of all characters and return the resulting string.

Requirements

  • Must return a string
  • Must work with special characters like punctuation

Example #1

solve('Hi Alex, will I see you in May?')
> 'hI aLEX, WILL i SEE YOU IN mAY?'