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Swift Repeat-While Loop

The repeat-while loop is a type of loop in Swift that is similar to the while loop. The main difference is that the repeat-while loop first executes the block of code and then checks the condition. This means that the block of code will always be executed at least once before the condition is checked.

Syntax

The syntax of the repeat-while loop in Swift is as follows:

repeat {
    // code to be executed
} while condition

The code inside the curly braces {} of the repeat block is executed at least once before the condition is checked. If the condition is true, the loop continues to execute the code block. If the condition is false, the loop exits and execution continues with the next statement after the loop.

Example

Here's an example of a repeat-while loop in Swift:

var i = 1
repeat {
    print(i)
    i += 1
} while i <= 5

In this example, the repeat-while loop executes the block of code inside the curly braces {} at least once. It then checks the condition i <= 5. If the condition is true, it executes the block of code again until the condition is false.

Output

The output of the above example will be:

1
2
3
4
5

Explanation

The repeat-while loop first executes the block of code inside the curly braces {}. In this example, it initializes the variable i to 1 and then prints its value to the console. It then increments the value of i by 1.

After the block of code executes, the loop checks the condition i <= 5. Since i is less than or equal to 5, the loop executes the block of code again, printing the new value of i and incrementing it by 1. This process continues until i is no longer less than or equal to 5.

Use

The repeat-while loop is used in Swift when you want to execute a block of code at least once, regardless of the condition. Some common use cases for the repeat-while loop include:

  • Validating user input
  • Reading data from a file or stream
  • Executing a block of code until a certain condition is met

Important Points

  • The repeat-while loop executes the block of code at least once before checking the condition.
  • The condition is checked after the code block executes.
  • The loop will execute as long as the condition is true.
  • The repeat-while loop is best used when you need to execute a block of code at least once, regardless of the condition.

Summary

The repeat-while loop is a useful construct in Swift that executes a block of code at least once, and then any number of times after that until a condition is met. It is a great tool for validating input, reading data, and executing code until a certain condition is met. If you need to execute a block of code at least once, the repeat-while loop is the perfect choice.

while loopStrings
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