The continue Keyword in Ruby

The keyword next is the ruby equivalent of the continue keyword in other programming languages. The next keyword allows you to skip one iteration.

Use the next Keyword to Skip One Iteration in Ruby Array

Add up all the even numbers in an array using the sum function. See example:

sum = 0
[1, 2, 3, 4].each do |num|
  next if num.odd?

  sum += num
end
puts sum

Output:

6

The next takes an argument and returns nil by default. When used with map or reduce, next might produce unexpected results.

We want to add 1 to each even number in an array.

[1, 2, 3, 4].map do |num|
  next if num.odd?

  num + 1
end

Output:

[nil, 3, nil, 5]

We need to pass next num if num.odd? to fix it.

[1, 2, 3, 4].map do |num|
  next num if num.odd?

  num + 1
end

Output:

[1, 3, 3, 5]