CODEWITHSUNDEEP
ruby
david
david

Reputation: 101

Call method with instance of itself in ruby

I'm new to ruby, and this might be an obvious question but I really have no idea what to search for on Google to actually find what I'm looking for.

I'm doing algorithmic problems (not really relevant), and it gives me a square matrix, and asks if it has circular symmetry. I solve it like this:

s = STDIN.readlines.map { |x| x.chomp }.join ''
puts %w[YES NO][s == s.reverse ? 0 : 1]

Is it possible to put all that in one line? The only reason I can't is because I think I have to store the string and then explicitly compare it later. And it sources the string from STDIN so I can't re-read it. Any elegant solutions? Thanks!

Upvotes: 1

Views: 82

Answers (2)

Mark Rushakoff
Mark Rushakoff

Reputation: 258138

Object#tap takes a block, and passes the object to that block. Thus, should be able to rewrite that as:

STDIN.readlines.map { |x| x.chomp }.join('').tap { |s| puts %w[YES NO][s == s.reverse ? 0 : 1] }

Although I agree with the commenter that this is only going to hurt readability.

Upvotes: 2

tadman
tadman

Reputation: 211540

Disregarding readability, you can almost always force things on to a single line by using the ; separator.

In your case since s is referenced twice you need to assign it to a variable.

Upvotes: 0

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