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I know of the ||= operator, but don't think it'll help me here...trying to create an array that counts the number of "types" among an array of objects.
array.each do |c|
newarray[c.type] = newarray[c.type] ? newarray[c.type]+1 ? 0
end
Is there a more graceful way to do this?
202
It turns out that the author of Ruby, matz suggests the official way to increment and decrement variables in ruby is by using the += and -= operators.
keys . Because the Ruby 1.9 Set library happens to be built upon a Hash currently, you can currently use Set as an ordered set.
JavaScript has an even more succinct syntax to increment a number by 1. The increment operator ( ++ ) increments its operand by 1 ; that is, it adds 1 to the existing value. There's a corresponding decrement operator ( -- ) that decrements a variable's value by 1 . That is, it subtracts 1 from the value.
Ruby has no pre/post increment/decrement operator. For instance, x++ or x-- will fail to parse. More importantly, ++x or --x will do nothing! In fact, they behave as multiple unary prefix operators: -x == ---x == -----x == ......
types = Hash.new(-1) # It feels like this should be 0, but to be
# equivalent to your example it needs to be -1
array.each do |c|
types[c.type] += 1
end
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