While

While loops will run as long as the condition is truthy.

Parentheses around conditions are optional.

Print numbers from 0 to 3:

🚀 > a = 0
🚀 > while a != 4
  puts(a)
  a = a + 1
end

// which prints
0
1
2
3
=> nil

It is possible to use next or break inside a while loop.

i = 0
while i < 10
  if i < 3
    i = i + 1
    next
  end
  puts(i)
  if i == 6
    break
  end
  i = i + 1
end

// which prints
3
4
5
6

Return Value

Loops do return the variable they are iterating after the last loop.

def iterate(items)
  foreach item in items
    puts(item)
  end
end

a = [1,2,3,4,5]

b = iterate(a)

// b is now [1,2,3,4,5]