Mastering Swift Loops: for-in, while, and repeat-while

Swift programming language provides several ways to iterate over a sequence. In this blog post, we will take a look at three of the most commonly used looping mechanisms, namely for-in, while, and repeat-while.

The for-in loop is one of the simplest and most powerful looping structures available in Swift. It allows you to iterate over a collection of items such as an array or a dictionary. Here is an example of a for-in loop that prints out the elements of an array:

let numbers = [1, 2, 3, 4, 5]

for number in numbers {
    print(number)
}
// prints 1, 2, 3, 4, 5

As you can see, the for-in loop is easy to use and understand. It also provides a concise and efficient way to iterate over a collection of items.

The while loop is another looping mechanism that is commonly used in Swift programming. It is similar to the for-in loop, but it allows you to specify a condition that must be met before the loop will terminate. Here is an example of a while loop that prints out the numbers from 1 to 10:

var i = 1
while i <= 10 {
    print(i)
    i += 1
}
// prints 1, 2, 3, 4, 5, 6, 7, 8, 9, 10

The while loop is useful when you want to continue looping until a certain condition is met.

Finally, the repeat-while loop is a variation of the while loop. It is similar to the while loop, but it checks the condition at the end of the loop instead of at the beginning. This means that the loop will always execute at least once. Here is an example of a repeat-while loop that prints out the numbers from 1 to 10:

var i = 1
repeat {
    print(i)
    i += 1
} while i <= 10
// prints 1, 2, 3, 4, 5, 6, 7, 8, 9, 10

The repeat-while loop is useful when you want to ensure that the loop will execute at least once.

In summary, Swift provides three looping mechanisms for iterating over a sequence: for-in, while, and repeat-while. Each of these looping structures has its own advantages and disadvantages, so it is important to choose the right looping structure for your specific needs. With a good understanding of these looping mechanisms, you can easily create powerful and efficient code in Swift.