JavaScript Operators

Introduction to Operators

Operators are used to perform operations on variables and values.

Types of Operators:

• Arithmetic Operators
• Assignment Operators
• Comparison Operators
• Logical Operators
• String Operators
• Unary Operators
• Ternary Operator

Arithmetic Operators

• + : Addition
• - : Subtraction
• * : Multiplication
• / : Division
• % : Modulus (Remainder)
• ** : Exponentiation
• ++ : Increment
• -- : Decrement

let a = 10, b = 3;
console.log(a + b); // 13
console.log(a % b); // 1
console.log(a ** b); // 1000
            

Assignment Operators

Used to assign values to variables:

• = : Assign
• += : Add and assign
• -= : Subtract and assign
• *=, /=, %= : Multiply/Divide/Modulus and assign

let x = 5;
x += 3; // x = x + 3 → 8
            

Comparison Operators

• == : Equal (type conversion)
• === : Strict equal (no conversion)
• !=, !== : Not equal
• >, <, >=, <=

console.log(5 == '5');  // true
console.log(5 === '5'); // false
            

Logical Operators

• && : Logical AND
• || : Logical OR
• ! : Logical NOT

let age = 20;
console.log(age > 18 && age < 30); // true
            

String Operator

The + operator can also be used to concatenate strings:

let firstName = "John";
let lastName = "Doe";
console.log(firstName + " " + lastName); // John Doe
            

Ternary Operator

Short-hand for if-else:

let age = 18;
let result = (age >= 18) ? "Adult" : "Minor";
console.log(result); // Adult
            

Examples:

// Arithmetic
let x = 5 + 3;  // 8

// Assignment
let y = 10;
y += 5;         // 15

// Comparison
let isEqual = (x == y);  // false

// Logical
let result = (x > 3 && y < 20);  // true

// String
let greeting = "Hello" + " " + "World";  // "Hello World"

// Conditional
let age = 18;
let canVote = (age >= 18) ? "Yes" : "No";