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iOS Swift Basics (retired) Control Flow While and Do-While Loop

While And Do-While Loop

I need a better explanation of the correct use of While and Do-While Loop for Swift, because I don't get to understand the video.

1 Answer

Stone Preston
Stone Preston
42,016 Points

while loops run some code while a certain condition is true. do while loops run an action at LEAST once, and then continue to loop if a certain condtion is true.

you can use a while loop to do something as long as a condition is met

var score = 0
while score < 10 {

     println("The score is less than 10)
     score++
}

the above loop will continue to print out "the score is less than 10" for as long as the score is less than 10. since it starts at 0 and we increment it every time, the loop will stop running once the score hits 10.

a do while loop is used when you need the loop to run at least once.

// it will print at least once time, even if x is not equal to 10
do {
  println(x)
} while (x == 10)

the while loop is much more common than the do while loop in my experience. but even then you dont really use a while loop that much. the for in loop is probably the one that gets used most

Thanks, that helped me understand the while situation much more clearly.