Operators in JavaScript

Why Do We Need Operators?

Imagine you’re building a small calculator or even a login system.

• You need to add numbers

• You need to compare values

• You need to make decisions (like “if user is logged in AND has access”)

That’s where operators come in.

Operators are just symbols that perform actions on values.

Think of them like tools:

• + → adds numbers

• > → checks which number is bigger

• && → checks multiple conditions

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What Are Operators?

Operators are symbols used to perform operations on data.

Simple example:

let result = 2 + 3;
console.log(result); // 5

Here:

• 2 and 3 are values

• + is the operator

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Types of Operators We’ll Learn

We’ll cover:

• Arithmetic

• Comparison

• Logical

• Assignment

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Arithmetic Operators (Basic Math)

These are the ones you already know from school.

let a = 10;
let b = 3;

console.log(a + b); // 13 (addition)
console.log(a - b); // 7  (subtraction)
console.log(a * b); // 30 (multiplication)
console.log(a / b); // 3.33 (division)
console.log(a % b); // 1 (remainder)

Real-Life Analogy

• + → total money you have

• - → money spent

• % → leftover after dividing something

Example: If you divide 10 chocolates among 3 people → 1 is left → %

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Comparison Operators (Checking Values)

These operators compare values and return true or false.

console.log(5 > 3);  // true
console.log(5 < 3);  // false
console.log(5 == '5'); // true
console.log(5 === '5'); // false

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Important: == vs ===

This is where beginners often get confused.

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

Why?

• == → checks value only (ignores type)

• === → checks value AND type

Simple Way to Remember

• == → “loose check”

• === → “strict check” (recommended)

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Logical Operators (Combining Conditions)

Used when you have multiple conditions.

let age = 20;
let hasID = true;

console.log(age > 18 && hasID); // true
console.log(age > 18 || false); // true
console.log(!true); // false

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How They Work

AND (&&)

Both must be true

true && true  // true
true && false // false

OR (||)

At least one must be true

true || false // true
false || false // false

NOT (!)

Reverses value

!true  // false
!false // true

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Assignment Operators (Storing Values)

Basic one:

let x = 10;

Now shortcut versions:

x += 5; // x = x + 5 → 15
x -= 3; // x = x - 3 → 12

Why Use Them?

They make code shorter and cleaner.

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Before vs After (Cleaner Code)

Without Shortcut

let score = 10;
score = score + 5;

With Shortcut

let score = 10;
score += 5;

Same result, cleaner code.

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Real-Life Example (Putting It Together)

let marks = 75;

if (marks >= 50 && marks <= 100) {
  console.log("Passed");
}

Here:

• >= and <= → comparison

• && → logical

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Practice Assignment

Try these step by step:

1. Arithmetic Operations

let a = 8;
let b = 2;

// perform +, -, *, /, %

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2. Compare Values

console.log(10 == '10');
console.log(10 === '10');

Observe the difference.

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3. Logical Condition

let age = 22;
let hasLicense = true;

// check if person can drive

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4. Assignment Practice

let score = 50;

// increase by 10 using +=
// decrease by 5 using -=