For Loop in Swift

In this tutorial, we will learn about for loops in Swift. We will cover the basics of iterative execution using for loops.

What is a For Loop

A for loop is a control flow statement that allows code to be executed repeatedly based on a given Boolean condition. The loop is typically used when the number of iterations is known before entering the loop.

Syntax

The syntax for the for loop in Swift is:

for item in iterable {
    // Code block to be executed
}

The for loop iterates over each item in the iterable object (such as a range or an array) and executes the code block for each item.


Example 1: Printing Numbers from 1 to 10

  1. Use a for loop to print numbers from 1 to 10.

Swift Program

for i in 1...10 {
    print("(i) ", terminator: "")
}

Output

1 2 3 4 5 6 7 8 9 10

Example 2: Calculating the Factorial of a Number

  1. Use a for loop to calculate the factorial of a number.

Swift Program

let n = 5
var factorial = 1
for i in 1...n {
    factorial *= i
}
print("Factorial of (n) is (factorial)")

Output

Factorial of 5 is 120

Example 3: Summing the Elements of an Array

  1. Use a for loop to calculate the sum of the elements in an array.

Swift Program

let arr = [1, 2, 3, 4, 5]
var sum = 0
for num in arr {
    sum += num
}
print("Sum of the elements in the array is (sum)")

Output

Sum of the elements in the array is 15