When writing programs in JavaScript, we often perform operations such as:

• Adding numbers

• Comparing values

• Checking conditions

To perform these actions, JavaScript provides operators.

Operators help us manipulate values and perform calculations in code.

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What Are Operators?

An operator is a symbol used to perform an operation on values.

Example:

let result = 5 + 3;

Here:

• 5 and 3 are operands

• + is the operator

Output:

8

Operators allow JavaScript to perform mathematical operations, comparisons, and logical checks.

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Arithmetic Operators

Arithmetic operators are used to perform mathematical calculations.

Operator	Meaning	Example
+	Addition	5 + 3
-	Subtraction	5 - 3
*	Multiplication	5 * 3
/	Division	6 / 3
%	Modulus (remainder)	7 % 2

Example:

let a = 10;
let b = 5;

console.log(a + b);
console.log(a - b);
console.log(a * b);
console.log(a / b);
console.log(a % b);

Output:

15
5
50
2
0

The % operator returns the remainder after division.

Example:

7 % 2 = 1

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Comparison Operators

Comparison operators compare two values and return true or false.

Operator	Meaning
==	Equal to
===	Strict equal
!=	Not equal
>	Greater than
<	Less than

Example:

console.log(5 > 3);
console.log(5 < 3);
console.log(5 == "5");
console.log(5 === "5");

Output:

true
false
true
false

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Difference Between == and ===

This is a very important concept.

== (Loose Equality)

Compares values only.

console.log(5 == "5");

Output:

true

JavaScript converts the string "5" into a number.

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=== (Strict Equality)

Compares value AND data type.

console.log(5 === "5");

Output:

false

Because:

• 5 → number

• "5" → string

Best practice: prefer === in most cases.

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Logical Operators

Logical operators are used when working with conditions.

Operator	Meaning
&&	AND
`
!	NOT

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Logical AND &&

Returns true only if both conditions are true.

let age = 20;

console.log(age > 18 && age < 30);

Output:

true

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Logical OR ||

Returns true if at least one condition is true.

console.log(5 > 10 || 10 > 5);

Output:

true

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Logical NOT !

Reverses a boolean value.

console.log(!true);

Output:

false

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Truth Table for Logical Operators

| A | B | A && B | A || B | | --- | --- | --- | --- | | true | true | true | true | | true | false | false | true | | false | true | false | true | | false | false | false | false |

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Assignment Operators

Assignment operators assign values to variables.

Operator	Example	Meaning
=	x = 5	Assign value
+=	x += 2	Add and assign
-=	x -= 2	Subtract and assign

Example:

let x = 10;

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

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

Output:

15
12

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Assignment Practice

Perform Arithmetic Operations

let a = 8;
let b = 4;

console.log(a + b);
console.log(a - b);
console.log(a * b);
console.log(a / b);

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Compare Values Using == and ===

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

Output:

true
false

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Logical Operator Example

let age = 22;

if (age > 18 && age < 60) {
  console.log("Eligible to work");
}

Output:

Eligible to work

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Operator Categories Summary

Category	Operators
Arithmetic	+ - * / %
Comparison	== === != > <
Logical	`&&
Assignment	= += -=

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