JavaScript: Reverse the bits of a given 16 bits unsigned short integer

JavaScript Basic: Exercise-138 with Solution

Write a JavaScript program to reverse the bits of a given 16-bit unsigned short integer.

Sample Solution:

JavaScript Code:

/**
 * Function to reverse the binary representation of a 16-bit number
 * @param {number} num - The input number
 * @returns {number} - The reversed binary number
 */	
function sixteen_bits_reverse(num) {
    var result = 0; // Initialize result to store the reversed number
    for (var i = 0; i < 16; i++) {
        result = result * 2 + (num % 2); // Reversing the bits by shifting result left and adding the last bit of 'num'
        num = Math.floor(num / 2); // Right-shifting 'num' to access the next bit
    }
    return result; // Return the reversed 16-bit number
}

console.log(sixteen_bits_reverse(12345));  
console.log(sixteen_bits_reverse(10));   
console.log(sixteen_bits_reverse(5));    

Output:

39948
20480
40960

Live Demo:

See the Pen javascript-basic-exercise-137 by w3resource (@w3resource) on CodePen.

Flowchart:

ES6 Version:

/**
 * Function to reverse the bits of a number considering 16 bits
 * @param {number} num - The input number
 * @returns {number} - The result after reversing the bits (considering 16 bits)
 */
const sixteen_bits_reverse = (num) => {
	let result = 0; // Variable to store the result after reversing bits, initialized to 0
	for (let i = 0; i < 16; i++) {
		result = result * 2 + (num % 2); // Multiplying the result by 2 and adding the last bit of 'num'
		num = Math.floor(num / 2); // Dividing 'num' by 2 (integer division)
	}
	return result; // Returning the final result after reversing 16 bits
};

console.log(sixteen_bits_reverse(12345));  
console.log(sixteen_bits_reverse(10));    
console.log(sixteen_bits_reverse(5));     

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