break and return in ruby, how do you use them?

Question

I just asked a question about return and it seems to do the same thing as break. How do you use return, and how do you use break, such as in the actual code that you write to solve the problems that can use these constructs.

I can't really post examples because I don't know how to use these so they wouldn't make much sense.

Answer 1

Return exits from the entire function.

Break exits from the innermost loop.

Thus, in a function like so:

def testing(target, method)
  (0..100).each do |x|
    (0..100).each do |y|
     puts x*y
     if x*y == target
       break if method == "break"
       return if method == "return"
     end
    end 
  end
end

To see the difference, try:

testing(50, "break")
testing(50, "return")

Answer 2

break is called from inside a loop. It will put you right after the innermost loop you are in.

return is called from within methods. It will return the value you tell it to and put you right after where it was called.

Answer 3

I wanted to edit the approved answer to simplify the example, but my edit was rejected with suggestion of making new answer. So this is my simplified version:

def testing(target, method)
  (1..3).each do |x|
    (1..3).each do |y|
     print x*y
     if x*y == target
       break if method == "break"
       return if method == "return"
     end
    end 
  end
end

we can see the difference trying:

testing(3, "break")
testing(3, "return")

Results of first (break statement exiting innermost loop only when 3 reached):

1232463

Results of last (return statement exiting whole function):

123

Answer 4

One more example could be if you have two loops in a single method and if you want to come out of the first loop and continue to the second loop use break in the first loop or vice versa:

def testing(method)
x=1
  10.times do
    if(x == 2)
     break if method == "break"
    end
   x+=1
  end
  10.times do
   if(x == 5)
     return if method == "return"
   end
  x+=1
  end 
end