> For the complete documentation index, see [llms.txt](https://mayanktyagi3111.gitbook.io/interview-prep/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://mayanktyagi3111.gitbook.io/interview-prep/bit-manipulation/number-of-1-bits.md).

# Number of 1 Bits

Write a function that takes an unsigned integer and returns the number of `1` bits it has.

**Example:**

The 32-bit integer `11` has binary representation

```
00000000000000000000000000001011
```

so the function should return `3`.

*Note that since Java does not have unsigned int, use long for Java*

```java
public class Solution {
    public int numSetBits(long n) {
        int count=0;
        while(n!=0){
            if((n&1)==1)
                count++;
            n=n>>1;
        }
        return count;
    }
}
```