Ruby - Why do "each" and "map" output differently?

Question

"each" outputs 1,2,3, whilst "map" outputs -1,-2,-3

arr = [1,2,3]
puts arr.each{|x| x = -x}
puts arr.map{|x| x = -x}

Answer 1

I don't code ruby but if it is like js forEach and map:

arr.each iterates causing side effects without mutation. It executes the callback on each element without changing the original values.

arr.map causes a mutation. Original values are changed to the value returned by the caklback.