Using Swift while and repeat-while Loops: How to Get Started

Swift is a powerful programming language that allows developers to write code quickly and efficiently. It is the language of choice for many iOS and MacOS applications. One of the great features of Swift is its ability to handle loops. Loops are a great way to execute code multiple times with minimal effort. In this tutorial, we will discuss two of the most common looping structures in Swift – while and repeat-while loops.

The while loop is one of the most basic looping structures in Swift. It executes a block of code until a certain condition is met. The syntax for a while loop is as follows:

while condition {
    // Code to be executed
}

In the above syntax, the condition is evaluated at the beginning of each loop iteration. If the condition is true, the code inside the loop is executed. If the condition is false, the loop is terminated and execution continues on the next line of code.

Let’s look at a practical example of a while loop. Suppose we want to print the numbers 1 to 10. We can use a while loop to accomplish this task:

var i = 1

while i <= 10 {
    print(i)
    i += 1
}

In the above example, we initialize a variable i and set it to 1. We then create a while loop that checks if i is less than or equal to 10. If it is, the code inside the loop is executed which prints the value of i and increments i by 1. This process is repeated until i is no longer less than or equal to 10. At that point, the loop terminates and execution continues on the next line of code.

The repeat-while loop is similar to the while loop, but it evaluates the condition at the end of the loop instead of the beginning. This means that the code inside the loop is always executed at least once. The syntax for a repeat-while loop is as follows:

repeat {
    // Code to be executed
} while condition

Let’s look at an example of a repeat-while loop. Suppose we want to print the numbers 1 to 10. We can use a repeat-while loop to accomplish this task:

var i = 1

repeat {
    print(i)
    i += 1
} while i <= 10

In the above example, we initialize a variable i and set it to 1. We then create a repeat-while loop that prints the value of i and increments i by 1. This process is repeated until i is no longer less than or equal to 10. At that point, the loop terminates and execution continues on the next line of code.

Now that you know how to use while and repeat-while loops in Swift, you can start adding them to your projects. They are a great way to execute code multiple times with minimal effort. With practice, you will become a master of loops in no time!