Possible Duplicate:
How to sum array members in Ruby?
Lets say I have this array
@test = [1, 2, 3, 4]
Then I want to do:
@test[0] + @test[1] + @test[2] + @test[3]
Is there not a smarter, faster way of doing this?
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2Look at this : stackoverflow.com/questions/1538789/…Jeremy D– Jeremy D2012-01-15 21:43:53 +00:00Commented Jan 15, 2012 at 21:43
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2 Answers
You can do this:
@test.inject(:+)
5 Comments
tokland
folds need the identity as initial value :
@test.inject(0, :+)
Jesse Pollak
Not with ruby, if you don't supply an initial value, it uses the first value in the collection as the initial value: ruby-doc.org/core-1.9.3/Enumerable.html
Dave Newton
More directly: ruby-doc.org/core-1.9.3/Enumerable.html#method-i-inject
tokland
jesse, steenslag: not for empty inputs:
[].inject(:+). I guess the OP wants a generic solution, not for 4 elements.sum = 0
@test.each { |el| sum+=el }
1 Comment
tokland
that's ok for a lot of (imperative) languages, but in Ruby the (functional)
Enumerable#inject is the idiomatic solution.