Swift - While Loop

In Swift, the while loop is a control flow structure that repeatedly executes a block of code as long as a given condition is true. The loop might not execute at all if the condition is false at the start.

Basic Syntax:

while condition {
    // code to execute while the condition is true
}

Example:

Here's a basic example of a while loop that prints numbers from 1 to 5:

var count = 1

while count <= 5 {
    print(count)
    count += 1
}

// Outputs:
// 1
// 2
// 3
// 4
// 5

Characteristics:

Pre-condition Check: The condition of a while loop is checked before the execution of loop statements. Hence, it's possible that the loop body might not execute at all if the condition is false to begin with.
Use Cases: The while loop is often used when the number of iterations is unknown ahead of time. For instance, it can be used when reading data from a stream until the stream is empty.

Another Variant: `repeat-while` Loop

Swift also provides another variant of the while loop called the repeat-while loop (known in some languages as the do-while loop). This loop first executes the code inside the loop and then checks the condition. This ensures that the loop body is executed at least once.

repeat {
    // code to execute
} while condition

Example:

Here's an example to demonstrate the difference. Consider a scenario where count starts at 6:

var count = 6

while count <= 5 {
    print("This won't be printed.")
    count += 1
}

repeat {
    print("This will be printed once.")
    count += 1
} while count <= 5

In the example above, the code inside the while loop won't be executed because the condition is false at the start. However, the repeat-while loop will execute its body once before checking the condition.

In summary, use the while loop when you want to repeatedly execute a block of code based on a condition that's checked before each iteration. If you want to ensure the loop body runs at least once, consider using the repeat-while loop.

How to use while loop in Swift programming:
Description: The while loop in Swift repeats a block of code as long as a certain condition is true.
```
var count = 0

while count < 5 {
    print("Count: \(count)")
    count += 1
}
```

Conditional statements with while loop in Swift:

Description: You can use conditional statements within a while loop to control its flow.

var number = 0

while number < 5 {
    if number % 2 == 0 {
        print("Even")
    } else {
        print("Odd")
    }
    number += 1
}

Using break and continue in Swift while loop:
Description: The break statement exits the while loop prematurely, and continue skips the rest of the code in the current iteration.
```
var counter = 0

while true {
    print(counter)
    counter += 1

    if counter == 3 {
        break // Exits the loop
    }
}
```
Infinite while loop and exit conditions in Swift:
Description: An infinite while loop runs indefinitely until a break condition is met.
```
var i = 0

while true {
    print("Infinite Loop")

    i += 1
    if i == 5 {
        break
    }
}
```

Swift while loop with boolean conditions:

Description: The while loop can use boolean conditions to control its execution.

var isRunning = true
var counter = 0

while isRunning {
    print("Counter: \(counter)")

    counter += 1
    if counter == 3 {
        isRunning = false
    }
}

Nested while loops in Swift programming:

Description: You can nest while loops to create more complex iteration patterns.

var i = 1

while i <= 3 {
    var j = 1
    while j <= 3 {
        print("(\(i), \(j))")
        j += 1
    }
    i += 1
}

Swift - While Loop

Basic Syntax:

Example:

Characteristics:

Another Variant: repeat-while Loop

Example:

Another Variant: `repeat-while` Loop