Number of 1 Bits (Hamming Weight)

The "Number of 1 Bits" problem, also referred to as the Hamming weight calculation, is a common question in computer science that focuses on counting the number of 1 bits (set bits) in the binary representation of a number.

Problem Statement

Given a non-negative integer n, count and return the number of '1' bits (also known as set bits) in its binary representation.

JavaScript Solution

Here's a simple JavaScript function to solve this problem:

function hammingWeight(n) {
  let count = 0;
  while (n !== 0) {
    count += n & 1;
    n >>>= 1;
  }
  return count;
}

Breaking Down the Solution

• Initialize a Count Variable: let count = 0; initializes a variable to keep track of the number of 1 bits.

• Loop Until n is Zero: The loop while (n !== 0) {} continues until all bits of n have been checked.

• Count 1 Bits: count += n & 1; adds 1 to count if the least significant bit of n is 1.

• Right Shift n: n >>>= 1; performs a logical right shift on n, moving all bits to the right by one place. This step is crucial for checking the next bit in the next iteration.

• Return the Count: After all bits have been checked, the function returns the count of 1 bits.

Conclusion

Calculating the Hamming weight of a number is a fundamental operation in bit manipulation. This problem not only tests basic understanding of bitwise operations but also serves as a foundation for more complex bit manipulation challenges.