Ruby Iterators

Iterator is a concept used in object-oriented language. Iteration means doing one thing many times like a loop.

The loop method is the simplest iterator. They return all the elements from a collection, one after the other. Arrays and hashes come in the category of collection.

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Ruby Each Iterator

The Ruby each iterator returns all the elements from a hash or array.

Syntax:

(collection).each do |variable|  

  code...  

end

Here collection can be any array, range or hash.

Example:

#!/usr/bin/ruby   

(1...5).each do |i|   

   puts i   

end

Output:

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Ruby Times Iterator

A loop is executed specified number of times by the times iterator. Loop will start from zero till one less than specified number.

Syntax:

x.times do |variable|  

  code...  

end

Here, at place of x we need to define number to iterate the loop.

Example:

#!/usr/bin/ruby   

5.times do |n|   

  puts n   

end

Output:

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Ruby Upto and Downto Iterators

An upto iterator iterates from number x to number y.

Syntax:

x.upto(y) do |variable|  

  code  

end

Example:

#!/usr/bin/ruby   

1.upto(5) do |n|   

  puts n   

end

Output:

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Ruby Step Iterator

A step iterator is used to iterate while skipping over a range.

Syntax:

(controller).step(x) do |variable|  

  code  

end

Here, x is the range which will be skipped during iteration.

Example:

#!/usr/bin/ruby   

(10..50).step(5) do |n|   

  puts n   

end

Output:

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Ruby Each_Line Iterator

A each_line iterator is used to iterate over a new line in a string.

Example:

#!/usr/bin/ruby   

"All\nthe\nwords\nare\nprinted\nin\na\nnew\line.".each_line do |line|   

puts line   

end