With this function you can remove all characters that are not classed as letters. This is handy for preventing people from entering unwanted characters into a text entry (like entering "#" to force a new line).NOTE: This function only detects and returns the 26 letter English alphabet from A - Z (upper or lower case).
Argument Description string The string to convert to letters.
username = string_letters(username);
The above code will set the "username" variable to only hold the letter characters of the original string (id the original string was "MacSw33ny" the returned string would be "MacSwny").