Ruby tutorial session 17

Hi Readers,

Today we are going to learn how to write case statements in Ruby. Know about ruby blocks and some string operations with examples.

Case:

    x = 11 
    case x 
    when 0 
    when 1, 2..5 
      puts "Second branch" 
    when 6..10 
      puts "Third branch" 
    when *[11, 12] 
      puts "Fourth branch" 
    when String: puts "Fifth branch" 
    when /\d+\.\d+/ 
      puts "Sixth branch" 
    when x.to_s.downcase == "peter" 
      puts "Seventh branch" 
    else 
      puts "Eight branch" 
    end   

Blocks - Usage examples:

    # Iteration 
    [1, 2, 3].each { |item| puts item } 
     
    # Resource Management 
    File.open("file.txt", "w") do |file| 
      file.puts "foobar" 
    end 
     
    # Callbacks 
    widget.on_button_press do 
      puts "Got button press" 
    end 
     
    # Convention: one-line blocks use {...} and multiline 
    # blocks use do...end  

Common String Operations:

    "  ".empty? == true 
    IO.read(__FILE__).each_with_index { |line, i| puts "#{i}: #{line}" } 
    "abc".scan(/./).each { |char| char.upcase } 
    "we split words".split.join(", ") 
    "    strip space   ".strip 
    sprintf("value of %s is %.2f", "PI", 3.1416) 
    "I Go Ruby"[2, 2] == "I Go Ruby"[2..3] # => "Go"   

Hope you will understand this concepts. Next we will meet with different concept.

Please practice these to get hands on experience.

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