NEW: Get your ticket for Hacking with Swift Live 2019! >>

< Previous: For loops   Next: Repeat loops >

While loops

A second way of writing loops is using while: give it a condition to check, and its loop code will go around and around until the condition fails.

For example, we could use a while loop to simulate a child counting in a game of hide and seek: we start at one, count up to and including 20 while printing each number out, then after the loop print “Ready or not”.

Here’s how that looks in Swift:

var number = 1

while number <= 20 {
    print(number)
    number += 1
}

print("Ready or not, here I come!")

UPGRADE YOUR SWIFT Hacking with Swift Live is a new iOS conference taking place in the UK this July, with all profits going to charity. Come and learn the major new APIs announced at WWDC19 with sessions and hands-on tutorials – click here to learn more!

< Previous: For loops   Next: Repeat loops >
MASTER SWIFT NOW
Buy Testing Swift Buy Practical iOS 12 Buy Pro Swift Buy Swift Design Patterns Buy Swift Coding Challenges Buy Server-Side Swift (Vapor Edition) Buy Server-Side Swift (Kitura Edition) Buy Hacking with macOS Buy Advanced iOS Volume One Buy Advanced iOS Volume Two Buy Hacking with watchOS Buy Hacking with tvOS Buy Hacking with Swift Buy Dive Into SpriteKit Buy Swift in Sixty Seconds Buy Objective-C for Swift Developers Buy Beyond Code

Was this page useful? Let me know!

Average rating: 4.9/5

Click here to visit the Hacking with Swift store >>