Ruby | String capitalize! Method
capitalize! is a String class method in Ruby which is used to return a copy of the given string by converting its first character uppercase and the remaining to lowercase. The only difference between capitalize and capitalize! method is that capitalize! method will return nil if no changes are made.
Parameters: Here, str is the given string which is to be converted.
Returns: Copy of the string with the first character in uppercase and remaining in lowercase. And nil if no changes are made.