Operators in JavaScript

Arithmetic operators are used to perform basic mathematical operations on numeric values.

List of JavaScript Arithmetic Operators

Arithmetic Operator Examples

let x = 10;
let y = 3;

console.log(x + y); // Output: 13
console.log(x - y); // Output: 7
console.log(x * y); // Output: 30
console.log(x / y); // Output: 3.3333333333333335
console.log(x % y); // Output: 1
console.log(x ** y); // Output: 1000

Increment and Decrement Behavior

• x++ or x--: value changes after evaluation
• ++x or --x: value changes before evaluation

Comparison operators compare two values and return a Boolean value (true or false). They are commonly used in conditional logic.

JavaScript Comparison Operator Reference

Comparison Operator Examples

let a = 5;
let b = '5';

console.log(a == b);   // true (loose equality)
console.log(a === b);  // false (strict equality)
console.log(a != b);   // false
console.log(a !== b);  // true
console.log(a > 3);    // true
console.log(a < 10);   // true
console.log(a >= 5);   // true
console.log(a <= 4);   // false

Difference Between == and ===

• == compares values only
• === compares both value and type (recommended)

Logical operators are used to combine or invert Boolean values and expressions.

JavaScript Logical Operators

Logical Operator Examples

let isAdult = true;
let hasPermission = false;

let canEnter = isAdult && hasPermission; // false
let canView = isAdult || hasPermission;  // true
let isDenied = !hasPermission;           // true

Logical Operator Behavior

• && → true only if both conditions are true
• || → true if at least one condition is true
• ! → reverses the Boolean value

Assignment operators assign values to variables and include shorthand forms for updating values.

JavaScript Assignment Operators

Assignment Operator Examples

let x = 10;

x += 5;
console.log(x); // 15

x -= 3;
console.log(x); // 12

x *= 2;
console.log(x); // 24

x /= 4;
console.log(x); // 6

x %= 3;
console.log(x); // 0

x = 2;
x **= 3;
console.log(x); // 8

The ternary operator provides a concise alternative to an if-else statement.

Ternary Operator Syntax

let result = condition ? valueIfTrue : valueIfFalse;

Basic Ternary Operator Example

let age = 20;
let access = age >= 18 ? "Allowed" : "Denied";

console.log(access); // Output: "Allowed"

Nested Ternary Operator Example

let score = 85;
let grade = score >= 90 ? 'A' : score >= 80 ? 'B' : 'C';

console.log(grade); // Output: "B"

⚠️ Best Practice:
Avoid excessive nesting of ternary operators as it reduces readability. Use if-else when logic becomes complex.

JavaScript provides a rich set of operators to handle calculations, comparisons, logic, and assignments:

• Arithmetic operators perform mathematical operations
• Comparison operators evaluate conditions
• Logical operators combine or invert Boolean expressions
• Assignment operators simplify value updates
• Ternary operator offers a concise conditional syntax

Understanding and using these operators effectively is essential for writing clear, expressive, and efficient JavaScript code.