Question

Regarding ruby

- What is block argument ? What is equivalent of block argument in java ?

Answer 1

Blocks make a lot of sense on methods that are defined on collections like arrays and hashes.

Let’s have a look at some examples with arrays.

A block that accepts an argument looks like this:

[1, 2, 3, 4, 5].each do |number|
  puts "#{number} was passed to the block"
end

And, again, this is the same as:

[1, 2, 3, 4, 5].each { |number| puts "#{number} was passed to the block" }

So, for blocks, do |number| is the same that is def add_two (number) for a method definition, except that the method wants a name while a block is anonymous: |number| and (number) both are argument lists. The first one is used for blocks, the second one for methods.

In Java, we have lambda expressions similar to block arguments.