For Loop in TypeScript

In this tutorial, we will learn about for loops in TypeScript. 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 TypeScript is:

for (initialization; condition; increment) {
    // Code block to be executed
}

The for loop evaluates the initialization statement, then the condition. If the condition is true, the code block inside the loop is executed. After each iteration, the increment statement is executed, and the condition is re-evaluated. This process repeats until the condition becomes false.

Flowchart of For Loop

Example 1: Printing Numbers from 1 to 10

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

TypeScript Program

for (let i = 1; i <= 10; i++) {
    console.log(i);
}

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.

TypeScript Program

const n = 5;
let factorial = 1;
for (let i = 1; i <= n; i++) {
    factorial *= i;
}
console.log(`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.

TypeScript Program

const arr = [1, 2, 3, 4, 5];
let sum = 0;
for (let i = 0; i < arr.length; i++) {
    sum += arr[i];
}
console.log(`Sum of the elements in the array is ${sum}`);

Output

Sum of the elements in the array is 15