Getting De-railed

Anna's blog

Ruby Loop -- With a Twist

Decrementing loop:

Let’s start with a siimple decrementing loop in ruby:

This produces all integers from 100 to 1, each on a separate line:

To produce a slightly more legible output that does not crown our terminal, use print instead of puts


There is also a downto method:

My favorite – that I always conveniently forget about on the spot – is reverse_each

reverse_each is really a play on the regular each method used with a range, with would iterate through a loop in ascending order:

To go a little bit fancier and with needless amount of work really, populate and array from a range and then iterate over it:

Let’s not forget the step method:

Decrementing | incrementing loop:

What if the task is to have the x counting down, but to have the integers in the output counting up?

There is a very simple mathematical solution to the problem:

The result is exactly what we are looking for:

(Here I also added a newline so that it does not clash with terminal prompt.)

I thought of this when asked on the spot, but it’s not exactly an elegant solution:

Incrementing counter | decrementing output:

Easy and more or less creative solution using a previously populated array for a counter that goes up from 1 to 100 and for an output that goes down from 100 to 1: