Seven Languages in Seven Weeks

My friend Timo recommended the book “Seven Languages in Seven Weeks” to me a couple of months ago.

During my parental leave I’ve finally found time to read -and more important-  code the exercises.

The first language is Ruby. Ruby is object-oriented, dynamically and strongly typed. It supports duck typing and is a good fit for developing DSLs.

Mac OS X comes with Ruby preinstalled.

The interactive console can be invoked with the command

$ irb 
irb(main):001:0>

Exercises

The famous Hello World is pretty simple:

puts 'Hello World!'

A loop can be constructed with while:

x = 0 
while x < 10   
    x = x + 1   
    puts "This is sentence number #{x}" 
end

For string extrapolation you have to use the double quotes.

Ruby has some nice string methods e.g. getting index of character sequences:

hello_ruby = "Hello Ruby!"
puts hello_ruby.index("Ruby")

A simple guessing game looks like this:

while true   
    random_number = rand(10)   
    puts "Guess the number!"   
    while true     
        guess = gets().to_i     
        puts "Too low" if guess < random_number     
        puts "too high" if guess > random_number     
        if guess == random_number       
            puts "Correct!"       
            break     
        end   
    end 
end

Sven Languages in Seven Day on Amazon (Affiliate)