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

Last update on May 30 2022 10:00:38 (UTC/GMT +8 hours)

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 integer.

Pictorial Presentation:

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

Sample Solution:

HTML Code:

<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width">
  <title> Calculate the sum of n + n/2 + n/4 + n/8 + ....</title>
</head>
<body>

</body>
</html>

JavaScript Code:

function int_sum(num) {
    var s_sum = 0;
    while (num > 0) {
        s_sum += num;
        num = Math.floor(num / 2);
    }
    return s_sum;
}
console.log(int_sum(8))
console.log(int_sum(9))
console.log(int_sum(26))

Sample Output:

15
16
49

Flowchart:

ES6 Version:

function int_sum(num) {
    let s_sum = 0;
    while (num > 0) {
        s_sum += num;
        num = Math.floor(num / 2);
    }
    return s_sum;
}
console.log(int_sum(8))
console.log(int_sum(9))
console.log(int_sum(26))

Live Demo:

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

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JavaScript: Tips of the Day

How to insert an item into an array at a specific index (JavaScript)?

What you want is the splice function on the native array object.

arr.splice(index, 0, item); will insert item into arr at the specified index (deleting 0 items first, that is, it's just an insert). In this example we will create an array and add an element to it into index 2:

var arr = []; arr[0] = "Jani"; arr[1] = "Hege"; arr[2] = "Stale"; arr[3] = "Kai Jim"; arr[4] = "Borge"; console.log(arr.join()); arr.splice(2, 0, "Lene"); console.log(arr.join());

Ref: https://bit.ly/2BXbp04