Swift Programming: The Big Nerd Ranch Guide, 3rd Edition

while Loops

A while loop executes the code inside its body for as long as a specified condition is true. You can write while loops to do many of the same things you have seen in for loops above. Start with a while loop that replicates the for loop in Example 6.1, “A for-in loop”:

Example 6.5. A while loop

...
var i = 1
while i < 6 {
    myFirstInt += 1                                        (5 times)
    print(myFirstInt)                                      (5 times)
    i += 1                                                 (5 times)
}

Figure 6.5, “while loop diagram” shows the flow of execution in this code.

Figure 6.5. while loop diagram

This while loop initializes a control variable (var i = 1), evaluates a condition (i < 6), executes code if the condition is valid (myFirstInt ...