Ruby vs. Java comparison

Ruby vs. Java

Ruby is terse. Getters and setters example.
Java:
Class Circle {
  private Coordinate center, float radius;

  public void setCenter(Coordinate center) {
    this.center = center;
  }

  public Coordinate getCenter() {
    return center;
  }

  public void setRadius(float radius) {
    this.radius = radius;
  }

  public float getRadius() {
    return radius;
  }
}

Ruby:
class Circle
  attr_accessor :center, :radius
end

Ruby uses dynamic typing (values have type, variables not), which decreases language complexity (no type declaration, no type casting) and increases flexibility.

Java:
public static int len(List list) {
  int x = 0;
  Iterator listIterator = list.iterator();
  while (listIterator.hasNext()) {
    x += 1
  }
  return x;
}

Ruby:
def len(list)
  x = 0;
  list.each do |element|
    x += 1;
  end
  x
end

Playing with lists.

Java:
List<String> languages = new LinkedList<String>();
languages.add("Java");
langauges.add("Ruby");
languages.add("Python);

Ruby:
languages = ["Java", "Ruby", "Python"]

# or
languages = %w{Java Ruby Python}

Simple iteration.
Java:
for (int i = 1; i <= 100; i++) {
  System.out.println(i);
}

Ruby:
for i in 1..100 do
  puts i
end

Everything is a object in Ruby.
Ruby:
1.class # => Fixnum

Core classes can be extended easily in Ruby.
Ruby:
class Fixnum
  def +(i)
    self - 1
  end
end
1 + 1 # => 0

Ruby metaprogramming.
speaker = Class.new
speaker.class_eval do
  def speak
    puts "Hello World"
  end
end
instance = speaker.new
instance.speak
# => Hello World