# JavaScript: Calculate the sum of n + n/2 + n/4 + n/8 + ....

## JavaScript Basic: Exercise-113 with Solution

Write a JavaScript program to calculate the sum of n + n/2 + n/4 + n/8 + .... where n is a positive integer and all divisions are integers.

**Visual Presentation:**

**Sample Solution: **

**JavaScript Code:**

```
// Function to calculate the sum of integers from 1 to num using bitwise operation
function int_sum(num) {
var s_sum = 0; // Initialize the sum variable
while (num > 0) { // Loop until num is greater than 0
s_sum += num; // Add num to the sum
num = Math.floor(num / 2); // Divide num by 2 using floor division
}
return s_sum; // Return the sum of integers from 1 to num
}
// Examples to calculate the sum of integers from 1 to the given number
console.log(int_sum(8));
console.log(int_sum(9));
console.log(int_sum(26));
```

Output:

15 16 49

**Live Demo: **

See the Pen javascript-basic-exercise-113 by w3resource (@w3resource) on CodePen.

**Flowchart: **

**ES6 Version:**

```
// Function to calculate the sum of integers from 1 to num using bitwise operation
const int_sum = (num) => {
let s_sum = 0; // Initialize the sum variable
while (num > 0) { // Loop until num is greater than 0
s_sum += num; // Add num to the sum
num = Math.floor(num / 2); // Divide num by 2 using floor division
}
return s_sum; // Return the sum of integers from 1 to num
}
// Examples to calculate the sum of integers from 1 to the given number
console.log(int_sum(8));
console.log(int_sum(9));
console.log(int_sum(26));
```

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