[RUBY] About array multiplication

I have a stumbling block due to a ruby problem, so I will keep it as a record.

The following is a rough explanation of the problem. ・ Two numbers are entered as a character string ("a b") ・ I want to give a number that doubles each final

Wrong answer

num = gets.split.map(&:to_i)
puts num * 2
  1. Split the value with the split method and put the string value in the array.

  2. Create an array by converting the values of the array to numbers with `map (&: to_i)`. (Regarding ``` map (&: to_i)` ``, the following article is very easy to understand and I used it as a reference.) https://a-records.info/ruby-map-ampersand-colon-to_i/

  3. Perform * 2 on the elements of the array.

The result is as follows.

num = gets.split.map(&:to_i) //Enter 5 10
puts num * 2
Output result=> 5 10 5 10

I didn't understand why 5 10 was repeated twice even though I was converting to a number with @ map (&: to_i).


-Multiplication of an array creates a new array that repeats the same elements. The elements were repeated because we were doing * 2 on the array itself, not on each element. (I think that's the case if you review it after understanding it ...)

num = gets.split.map(&:to_i)
num.each {|n| puts n * 2}

It was solved by processing each element with `ʻeach``.

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