Skip to content

Added SetBit.js, SetBit.test.js in Bit-Manipulation directory #632

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 6 commits into from
Jul 5, 2021
Merged
Show file tree
Hide file tree
Changes from all commits
Commits
File filter

Filter by extension

Filter by extension

Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
31 changes: 31 additions & 0 deletions Bit-Manipulation/SetBit.js
Original file line number Diff line number Diff line change
@@ -0,0 +1,31 @@
/*
* Setting Bit: https://www.geeksforgeeks.org/set-k-th-bit-given-number/
*
* To set any bit we use bitwise OR (|) operator.
*
* Bitwise OR (|) compares the bits of the 32
* bit binary representations of the number and
* returns a number after comparing each bit.
*
* 0 | 0 -> 0
* 0 | 1 -> 1
* 1 | 0 -> 1
* 1 | 1 -> 1
*
* In-order to set kth bit of a number (where k is the position where bit is to be changed)
* we need to shift 1 k times to its left and then perform bitwise OR operation with the
* number and result of left shift performed just before.
*
* References:
* https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Bitwise_OR
*/

/**
* @param {number} number
* @param {number} bitPosition - zero based.
* @return {number}
*/

export const setBit = (number, bitPosition) => {
return number | (1 << bitPosition)
}
21 changes: 21 additions & 0 deletions Bit-Manipulation/test/SetBit.test.js
Original file line number Diff line number Diff line change
@@ -0,0 +1,21 @@
import { setBit } from '../SetBit'

test('Set bit number 0 in 1:', () => {
const setBitPos = setBit(1, 0)
expect(setBitPos).toBe(1)
})

test('Set bit number 0 in 2:', () => {
const setBitPos = setBit(2, 0)
expect(setBitPos).toBe(3)
})

test('Set bit number 1 in 10:', () => {
const setBitPos = setBit(10, 1)
expect(setBitPos).toBe(10)
})

test('Set bit number 2 in 10:', () => {
const setBitPos = setBit(10, 2)
expect(setBitPos).toBe(14)
})