JavaScript Program to Compute Power of a Number

In this article, we will demonstrate different approaches for computing the Power of a Number using JavaScript.

The Power of a Number can be computed by raising a number to a certain exponent. It can be denoted using a^b, where the ‘a’ represents the base number & the ‘b’ represents the number to which the power is to be raised. These programs will have input numbers and power and will show the resulting output. There are various techniques to calculate the power of a number, which are described below with their illustrations.

Using JavaScript Loops

In this method, we will use JavaScript for loop to iterate and calculate output by multiplication.

Example: In this example, we will calculate the output of 5 to power 3.

// Base number input
let n = 5

// Power input
let power = 3

// Result variable
let num = 1;
for (let i = 0; i < power; ++i) {
    num = num * n;
}

// Display output
console.log(num);

125

Using Recursion

In this method, we will use a recursive function to iterate and perform multiplication at every iteration.

Example: In this example, we will calculate 8 to the power 3 using recursion.

// Recursive function to compute Power
function pow(n, p) {
    if (p == 1) return n;
    return n * pow(n, p - 1);
}

// Base number input
let n = 8;

// Power input
let power = 3

// Display output
console.log(pow(n, power));

512

Using the Math.pow() Method

This is another method to method that is used to power a number i.e., the value of the number raised to some exponent. Here, we will use this method to calculate the power of the number.

Syntax

Math.pow(base, exponent);

Example: In this example, we will calculate 7 to power 9 using Math.pow() method.

// Base number input
let n = 7;
let power = 9;

// Calculate and display output
console.log(Math.pow(n,power));

40353607

Using JavaScript Exponentiation (**) Operator

This method can also be utilized to find the power of the first operator raised to the second operator, & it is denoted by a double asterisk(**) symbol.

Syntax

Base**Power

Example: In this example, we will use the JavaScript ** operator to get 17 to power 3.

// Base number input
let n = 17;
let power = 3;

// Calculate and display output
console.log(n**power);

4913

Using Exponentiation by Squaring

Exponentiation by Squaring is an efficient method for calculating large powers of a number. It reduces the number of multiplications required by breaking down the exponentiation process into smaller parts.

Example: In this example, we will calculate 2 to the power of 10 using Exponentiation by Squaring.

// Function to compute power using Exponentiation by Squaring
function powerBySquaring(base, exponent) {
    if (exponent === 0) return 1;
    if (exponent % 2 === 0) {
        let halfPower = powerBySquaring(base, exponent / 2);
        return halfPower * halfPower;
    } else {
        return base * powerBySquaring(base, exponent - 1);
    }
}

// Base number input
let base = 2;

// Power input
let exponent = 10;

// Calculate and display output
console.log(powerBySquaring(base, exponent));

1024