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.

Syntax:str.capitalize! 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.

Example 1: Ruby

# Ruby program to demonstrate
# the capitalize! method

# Taking the string and
# using the method
puts "ruby".capitalize!()
puts "gfg".capitalize!()

Output:

Ruby
Gfg

Example 2: Ruby

# Ruby program to demonstrate
# the capitalize! method

# Taking a string 
# already in uppercase
# it will not give any 
# output
puts "Geeksforgeeks".capitalize!()

puts "computer".capitalize!()

Output:

Computer