JavaScript - Bitwise Operators

Overview

Estimated time: 20–30 minutes

Bitwise operators work on 32-bit integers. Use them for masks, flags, and low-level operations.

Learning Objectives

• Use AND, OR, XOR, NOT, shifts.
• Understand signed vs unsigned right shift.

Prerequisites

• JavaScript - Logical Operators

Examples

const READ=1<<0, WRITE=1<<1, EXECUTE=1<<2;
let perm = READ | WRITE;           // 3
(perm & READ) !== 0;               // true
perm = perm & ~WRITE;              // remove WRITE

5 & 3   // 1
5 | 3   // 7
5 ^ 3   // 6
~5      // -6
5 << 1  // 10
5 >> 1  // 2
-5 >>> 1 // large positive (zero-fill)

Common Pitfalls

• All bitwise ops coerce to 32-bit signed integers (except >>> result is unsigned).