Swift - While Loop

A loop statement allows a program to execute a given block of codes repeatedly under a given condition. This enables a programmer to write programs in fewer lines of code and enhance the code readability. Swift has following types of loop to handle the looping requirements:

• while loop
• repeat-while loop
• for-in loop

The While Loop

While loop allows a set of statements to be executed repeatedly as long as a specified condition is true. The While loop can be viewed as a repeating if statement.

Syntax

while (condition) {
  statements
}

Flow Diagram:

In below mentioned example, program uses while loop to sum all integers from 1 to 5.

var i = 1
var sum = 0

while (i < 6) {
  sum = sum + i
  i = i + 1
}
print(sum) 

The output of the above code will be:

15

Consider one more example, where iterating variable i is printed in each iteration.

var i:Int = 100

while (i <= 1000) {
  print("Value of i = \(i)")
  i = i + 100
}

The output of the above code will be:

Value of i = 100
Value of i = 200
Value of i = 300
Value of i = 400
Value of i = 500
Value of i = 600
Value of i = 700
Value of i = 800
Value of i = 900
Value of i = 1000