Ruby Ruby Loops Ruby Iteration Iteration With Each

Andrew Walters
Andrew Walters
8,876 Points

What are the benefits to Iterations with Each compared to (while) loops?

Just curious, if (in the example) using a while loop and using iterations with each gives us the same result, why is it beneficial to use one over the other? Could you give me any real world application examples? Thanks

1 Answer

Andrew Stelmach
Andrew Stelmach
12,374 Points

You can use while and each iterations for the same thing, but there are things you can do with while that you can't do with each. So you can use either thing to, for example, iterate over every element in an array.

each will always 'do something' for every single element of whatever you are iterating over, UNLESS you use the handy break method:

array = ["Andy", "Bob", "Chris", "Paul"]
answer = ""

array.each do |name|
  answer = gets.chomp
  break if answer == name
end

So, we do have a way to halt an each iteration.

while will break out and cease an iteration when a certain condition is met by default:

array = ["Andy", "Bob", "Chris", "Paul"]
answer = ""
i = -1

while array[i] != answer do
  i += 1
  answer = gets.chomp
end

However, you could say that the above is not as clean nor readable as the first example.

However, you couldn't do something like the following with each:

name = ""
while name != "Andy" do
  name = gets.chomp
end

Nor:

array = []

while array.length < 5 do
  puts "Enter an item"
  item = gets.chomp
  array << item
end

Using until is probably more readable though in this case:

array = []

until array.length == 5 do
  puts "Enter an item"
  item = gets.chomp
  array << item
end

Cheers! Writing this made me realise a couple of things too.

Andrew Walters
Andrew Walters
8,876 Points

Thanks for the info! I thought it might've had to do with the neatness of the code, I just wasn't sure if there were any hidden benefits. I appreciate the help and I'm glad writing to me helped you out too! Cheers :)