bits.OnesCount64() Function in Golang with Examples

Go language provides inbuilt support for bits to implement bit counting and manipulation functions for the predeclared unsigned integer types with the help of bits package. This package provides OnesCount64() function which is used to find the number of one bits in a. To access OnesCount64() function you need to add a math/bits package in your program with the help of the import keyword.

Syntax: 

func OnesCount64(a uint64) int

Parameters: This function takes one parameter of uint64 type, i.e., a.

Return Value: This function returns the total number of one bits that are used to represent a.

Example 1 :

// Golang program to illustrate bits.OnesCount64() Function
package main

import (
    "fmt"
    "math/bits"
)

// Main function
func main() {

    // Using OnesCount64() function
    a := bits.OnesCount64(5)
    fmt.Printf("Total number of one bits "+
        "that are used to represent %d: %d", 5, a)

}

Output:

Total number of one bits that are used to represent 5: 2

Example 2 :

// Golang program to illustrate bits.OnesCount64() Function
package main

import (
    "fmt"
    "math/bits"
)

// Main function
func main() {
    // Using OnesCount64() function
    a1 := bits.OnesCount64(23)
    fmt.Printf("OnesCount64(%064b) := %d\n", 23, a1)

    a2 := bits.OnesCount64(13)
    fmt.Printf("OnesCount64(%064b) := %d\n", 13, a2)

}

Output:

OnesCount64(0000000000000000000000000000000000000000000000000000000000010111) := 4
OnesCount64(0000000000000000000000000000000000000000000000000000000000001101) := 3