JavaScript Program to Convert a Number to Binary

We are going to learn the conversion of a number to binary by using JavaScript, Convert a number to binary in JavaScript refers to the process of converting a decimal number into its binary representation, which uses only the digits 0 and 1 to represent the value

Converting a number to binary in JavaScript involves transforming a decimal (base 10) number into its binary (base 2) representation.

For example:

(25)10 = (11001)2
(32)10= (100000)2
(8)10= (1000)2

There are several methods that can be used to Convert a number to binary in JavaScript, which are listed below:

We will explore all the above methods along with their basic implementation with the help of examples.

Approach 1: Using toString() method

The built-in toString() method in JavaScript allows you to convert a number to a string representation in a given base. By providing a base of 2, you can convert a decimal number to its binary representation.

Syntax:

function decimalToBinary(decimalNumber) {
    return decimalNumber.toString(2);
};

Example: In this example we are using the above-explained approach.

function decimalToBinary(decimalNumber) {
    return decimalNumber.toString(2);
}

const decimalNum = 25;
const Result = decimalToBinary(decimalNum);
console.log(Result);

11001

Approach 2: Bit Manipulation Method

Bit manipulation is a technique where you manipulate individual bits of a number using bitwise operators. In the context of converting to binary, you can repeatedly extract the least significant bit (LSB) of the decimal number while shifting the number to the right.

Syntax:

for (; decimalNumber > 0;
    decimalNumber = Math.floor(decimalNumber / 2)) {
    binary = (decimalNumber % 2) + binary;
}

Example: In this example, The function decimalToBinary converts a decimal number to binary using a for loop. Bitwise operations shift the number's bits, constructing the binary representation.

function decimalToBinary(decimalNumber) {
    let binary = "";
    for (; decimalNumber > 0; decimalNumber >>= 1) {
        binary = (decimalNumber & 1) + binary;
    }
    return binary || "0";
}

const num1 = 32;
const Result = decimalToBinary(num1);
console.log(Result); 

100000

Approach 3: Recursive Method

The recursive method for converting a number to binary involves repeatedly dividing the number by 2 and appending remainders to the binary representation using a recursive function.

Syntax:

function convertDecimalToBinary(decimalNumber) {
    if (decimalNumber === 0) {
        //code..
    } else {
        //code...
    }
};

Example: In this example we are using the above-explained approach.

function convertDecimalToBinary(decimalNumber) {
    if (decimalNumber === 0) {
        // Base case: Return "0" if the number is 0
        return "0";
    } else {
        // Recursive case: Divide the number by 2, 
        //append the remainder to the result of the recursive call
        return convertDecimalToBinary(
            Math.floor(decimalNumber / 2)) + (decimalNumber % 2);

    }
}

const num1 = 10;
const result = convertDecimalToBinary(num1);
console.log(result);

01010

Approach 4: Using Array-Based Method

In this method, we use an array to collect the binary digits (bits) as we repeatedly divide the decimal number by 2. Once we have collected all the bits, we join them into a string to form the binary representation.

Example: In this example, we will use the above approach to convert a decimal number to binary.

function decimalToBinary(decimalNumber) {
    let binaryArray = [];
    while (decimalNumber > 0) {
        binaryArray.unshift(decimalNumber % 2);
        decimalNumber = Math.floor(decimalNumber / 2);
    }
    return binaryArray.length ? binaryArray.join('') : '0';
}

const decimalNum = 10;
const result = decimalToBinary(decimalNum);
console.log(result);

1010