Automatic counter in Ruby for each?

Question

I want to use a for-each and a counter:

i=0
for blah in blahs
    puts i.to_s + \" \" + blah
    i+=1
end

Is there a better way to do it?

Answer 1

If you want to get index of ruby for each, then you can use

.each_with_index

Here is an example to show how .each_with_index works:

range = ('a'..'z').to_a
length = range.length - 1
range.each_with_index do |letter, index|
    print letter + " "
    if index == length
        puts "You are at last item"
    end
end

This will print:

a b c d e f g h i j k l m n o p q r s t u v w x y z You are at last item

Answer 2

As people have said, you can use

each_with_index

but if you want indices with an iterator different to "each" (for example, if you want to map with an index or something like that) you can concatenate enumerators with the each_with_index method, or simply use with_index:

blahs.each_with_index.map { |blah, index| something(blah, index)}

blahs.map.with_index { |blah, index| something(blah, index) }

This is something you can do from ruby 1.8.7 and 1.9.