6-Operators

1. Definition

An operator in JavaScript is a symbol used to perform operations on operands (variables and values). Operators are essential for performing arithmetic, comparing values, assigning values, logical evaluation, and more.

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2. Types of JavaScript Operators

Category	Examples
Arithmetic Operators	+, -, *, /, %, **
Assignment Operators	=, +=, -=, *=, /=, etc.
Comparison Operators	==, ===, !=, !==, <, >
Logical Operators	&&, `
Unary Operators	typeof, ++, --, !, delete
Ternary Operator	condition ? expr1 : expr2
Bitwise Operators	&, `

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3. Arithmetic Operators

Used to perform mathematical calculations.

Operator	Description	Example	Output
+	Addition	2 + 3	5
-	Subtraction	5 - 2	3
*	Multiplication	4 * 2	8
/	Division	10 / 2	5
%	Modulus (remainder)	7 % 2	1
**	Exponentiation (ES6)	2 ** 3	8

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4. Assignment Operators

Used to assign values to variables.

Operator	Description	Example
=	Assign	x = 10
+=	Add and assign	x += 5 → x = x + 5
-=	Subtract and assign	x -= 3
*=	Multiply and assign	x *= 2
/=	Divide and assign	x /= 4
%=	Modulus and assign	x %= 2

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5. Comparison Operators

Used to compare values. Results in a boolean (true or false).

Operator	Description	Example	Output
==	Equal (type conversion allowed)	5 == '5'	true
===	Strict equal (no type conversion)	5 === '5'	false
!=	Not equal	5 != '5'	false
!==	Strict not equal	5 !== '5'	true
>	Greater than	6 > 3	true
<	Less than	3 < 6	true
>=	Greater than or equal	5 >= 5	true
<=	Less than or equal	5 <= 6	true

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6. Logical Operators

Used to combine multiple boolean expressions.

Operator	Description	Example	Output
&&	Logical AND	true && false	false
`		`	Logical OR
!	Logical NOT	!true	false

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7. Unary Operators

Work with only one operand.

a. typeof

• Returns the data type of a variable.

typeof "hello"; // "string"

b. ++ (Increment) / — (Decrement)

Increases or decreases a variable’s value by 1.

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let x = 5; x++; // 6

c. delete

Deletes a property from an object.

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let obj = {name: "John"}; delete obj.name; // obj becomes {}

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8. Ternary Operator (Conditional Operator)

Short form of if...else. Used for decision-making.

Syntax:

condition ? expressionIfTrue : expressionIfFalse

Example:

let age = 20; let status = age >= 18 ? "Adult" : "Minor"; // "Adult"

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9. Bitwise Operators

Operate on 32-bit binary numbers.

Operator	Description	Example	Output
&	AND	5 & 1	1
`	`	OR	`5
^	XOR	5 ^ 1	4
~	NOT	~5	-6
<<	Left shift	5 << 1	10
>>	Right shift	5 >> 1	2

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10. String Operators

Used to concatenate strings.

a. + (Concatenation)

"Hello" + " World"; // "Hello World"

b. +=

let str = "Hello"; str += " World"; // "Hello World"

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11. Spread and Rest Operators (...)

a. Spread

Expands elements of an array or object.

let nums = [1, 2, 3]; let copy = [...nums]; // [1, 2, 3]

b. Rest

Gathers remaining arguments into an array.

function sum(...args) {   return args.reduce((a, b) => a + b, 0); } sum(1, 2, 3); // 6`

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