Swiftly

Swift 5.1 references for busy coders

While

A while loop will run the code block each time the conditional is true. A repeat-while loop will run the block first without checking the conditional, then keep on running it as long as the conditional is true.

Simple while

var steps = 2
while steps > 0 {
  print("\(steps) steps left")
  steps -= 1
}
// Output:
// 2 steps left
// 1 steps left
var steps = -999
while steps > 0 {
  print("\(steps) steps left")
  steps -= 1
}
// Output: nothing

Repeat-while

var steps = 2
repeat {
  print("\(steps) steps left")
  steps -= 1
} while steps > 0
// Output:
// 2 steps left
// 1 steps left
var steps = -999
repeat {
  print("\(steps) steps left")
  steps -= 1
} while steps > 0
// Output: "-999 steps left"