Hello World
September 3rd, 2007As with any introduction to a programming language, I start off with a simple Hello World program. What takes me a minute to do in a language that I know, takes much longer with one that is foreign to me.
I’ll make this a bit more complicated, asking for the person’s name and telling them hello in my reply.
# Ask the user their name
puts "What is your name?"
user_name = gets
# Cunningly impress them with your response
puts "Hello, #{user_name.capitalize}!"
When I run the program and it asks for my name, I’ll type in Joe.
Output:
What is your name?
joe
Hello, Joe
!
The output of the program is not quite what I envisioned. The exclamation point appears on separate line. When I typed joe and pressed enter, the enter (or newline) is printed in the response. String object provides a method, chomp, that will move unwanted display characters, namely the enter key that I pressed. I’ll call chomp when I receive the input from the gets method.
# Ask the user their name
puts "What is your name?"
# Get the user name and remove newline characters
user_name = gets.chomp
# Cunningly impress them with your response
puts "Hello, #{user_name.capitalize}!"
Running the revised program, I hope that the response appears on one line when I tell the program that my name is Joe.
Output:
What is your name?
joe
Hello, Joe!
There you have it. My first Hello World program written in Ruby.