Question

I am java professional now I like to go for ruby.Are there any similarity in both the languages? and what are the major differences? As both are object oriented.

Answer 1

What about these:

Similarities

As with Java, in Ruby,…

• Memory is managed for you via a garbage collector.
• Objects are strongly typed.
• There are public, private, and protected methods.
• There are embedded doc tools (Ruby’s is called RDoc). The docs generated by rdoc look very similar to those generated by javadoc.

Differences

Unlike Java, in Ruby,…

• You don’t need to compile your code. You just run it directly.
• All member variables are private. From the outside, you access everything via methods.
• Everything is an object, including numbers like 2 and 3.14159.
• There’s no static type checking.
• Variable names are just labels. They don’t have a type associated with them.
• There are no type declarations. You just assign to new variable names as-needed and they just “spring up” (i.e. a = [1,2,3] rather than int[] a = {1,2,3};).
• There’s no casting. Just call the methods.
• The constructor is always named “initialize” instead of the name of the class.
• You have “mixin’s” instead of interfaces.
• == and equals() are handled differently in Ruby. Use == when you want to test equivalence in Ruby (equals() is Java). Use equal?() when you want to know if two objects are the same (== in Java).

Taken from: To Ruby From Java