07 - Operators in JavaScript.md

Operators in JavaScript

Introduction

In JavaScript, Operators are special symbols used to perform operations on variables and values.

Operators are used to:

• Perform arithmetic calculations
• Compare values
• Combine conditions
• Assign values
• Concatenate strings
• Make decisions using conditions

---

Types of Operators in JavaScript

JavaScript provides the following major types of operators:

1. Arithmetic Operators
2. Comparison Operators
3. Logical Operators
4. Ternary Operator
5. String Operators

---

1. Arithmetic Operators

Arithmetic operators are used to perform mathematical calculations.

Operator	Description	Example
+	Addition	a + b
-	Subtraction	a - b
*	Multiplication	a * b
/	Division	a / b
%	Modulus (Remainder)	a % b
++	Increment	a++
--	Decrement	a--

Example

var a = 10;
var b = 5;

console.log(a + b); // 15
console.log(a - b); // 5
console.log(a * b); // 50
console.log(a / b); // 2
console.log(a % b); // 0

Increment Operator

var a = 10;

console.log(a++); // 10
console.log(a);   // 11

console.log(++a); // 12

Explanation:

• a++ → Post Increment First returns the value, then increments.

• ++a → Pre Increment First increments the value, then returns it.

---

Decrement Operator

var b = 5;

console.log(b--); // 5
console.log(b);   // 4

console.log(--b); // 3

Explanation:

• b-- → Post Decrement
• --b → Pre Decrement

---

2. Comparison Operators

Comparison operators compare two values and return either:

true

or

false

Operator	Meaning
==	Equal to
!=	Not Equal to
===	Strict Equal
!==	Strict Not Equal
>	Greater Than
<	Less Than
>=	Greater Than or Equal
<=	Less Than or Equal

---

Example 1

var x = 10;
var y = "10";

console.log(x == y);

Output:

true

Reason:

== checks only values.

---

Example 2

var x = 10;
var y = "10";

console.log(x === y);

Output:

false

Reason:

=== checks:

• Value
• Data Type

10 → Number

"10" → String

Hence false.

---

More Examples

var x = 10;
var y = 20;

console.log(x != y);   // true

console.log(x !== y);  // true

console.log(x == y);   // false

console.log(x === y);  // false

console.log(x <= y);   // true

console.log(x >= y);   // false

---

3. Logical Operators

Logical operators are used to combine conditions.

Operator	Meaning
&&	Logical AND
!	Logical NOT

---

Logical AND (&&)

Returns true only when all conditions are true.

var a = 10;
var b = 20;

var c = (a < b && b > a);

console.log(c);

Output:

true

---

var a = 10;
var b = 20;

var c = (a > b && b > a);

console.log(c);

Output:

false

---

Logical OR (||)

Returns true if at least one condition is true.

var a = 10;
var b = 20;

var c = (a > b || b > a);

console.log(c);

Output:

true

---

var a = 10;
var b = 20;

var c = (a > b || b < a);

console.log(c);

Output:

false

---

Logical NOT (!)

Reverses the result.

var a = true;

console.log(!a);

Output:

false

---

4. Ternary Operator

The Ternary Operator is a shorthand form of an if-else statement.

Syntax

condition ? valueIfTrue : valueIfFalse;

---

Example

var n1 = 5;
var n2 = 10;

var result = n1 > n2 ? n1 : n2;

console.log(result);

Output:

10

Explanation:

If n1 > n2

return n1

Else

return n2

---

Another Example

var age = 20;

var status = age >= 18 ? "Eligible to Vote" : "Not Eligible";

console.log(status);

Output:

Eligible to Vote

---

5. String Operators

The + operator is also used for string concatenation.

It combines two or more strings.

---

Example

var str1 = "Hello ";
var str2 = "World";

var result = str1 + str2;

console.log(result);

Output:

Hello World

---

Example

var fname = "Shaik";

var lname = "Basha";

console.log(fname + " " + lname);

Output:

Shaik Basha

---

Difference Between == and ===

==	===
Checks only value	Checks value and datatype
Performs type conversion	No type conversion
10 == "10" → true	10 === "10" → false

---

Important Points

1. Operators are symbols used to perform operations.

2. Arithmetic operators perform calculations.

3. Comparison operators return true or false.

4. Logical operators combine multiple conditions.

5. Ternary operator is a shorthand for if-else.

6. The + operator can be used for both:

   • Addition
   • String Concatenation

7. === is preferred over == because it checks both value and datatype.

---

Summary

JavaScript Operators are one of the fundamental concepts of programming. They are used to perform calculations, compare values, combine conditions, make decisions, and manipulate strings. Understanding operators is essential because they are used throughout JavaScript applications, from basic programs to advanced web development and frameworks such as React, Angular, and Node.js.