Swift Programming: The Big Nerd Ranch Guide

while Loops

A while loop executes the code inside its body so long as a condition is true. You can write while loops to do many of the same things you have seen in for loops above. For example, a while loop that replicates the for loop in Listing 6.1 can be expressed like so:

Listing 6.5 A while loop

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

Figure 6.5 shows the flow of execution in this code.

Figure 6.5 while loop diagram

The flowchart starts from the “Set i to equal 1” flows to “Is i less than 6?” If yes, it leads to “Execute block” and if no, it leads to Exit. The “Execute block” in turn ...