How do I iterate through an array with an index? | Army of Minions

You’re probably familiar with iterating through an array or hash: Normally, you’d iterate through it with something like this:

	company_names = ["Tekfly", "Yabox", "Vinder", "Skiptube", "Fivespan"]

	company_names.each do \|company_name\|
	puts "#{company_name}"
	end

view raw company_names_each_no_index.rb hosted with ❤ by GitHub

Which would generate this output:

Tekfly
Yabox
Vinder
Skiptube
Fivespan

But what if we wanted to iterate through with an index (maybe for use in css or JavaScript identifiers in our view template)? That’s where each_with_index comes in.

Swap out each with each_with_index, put in a second argument for the index and you’re good to go!

	company_names = ["Tekfly", "Yabox", "Vinder", "Skiptube", "Fivespan"]

	company_names.each_with_index do \|company_name, index\|
	puts "#{company_name} has index #{index}"
	end

view raw company_names_each_with_index.rb hosted with ❤ by GitHub

This creates output like this:

Tekfly has index 0
Yabox has index 1
Vinder has index 2
Skiptube has index 3
Fivespan has index 4

For more information on each_with_index, check out the RubyDoc

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