Operators in JavaScript


Operators are special symbols or keywords used to perform operations on values or variables. They're the building blocks of logic and calculations in your programs.

JavaScript provides many types of operators, and each type does something different.


1. Arithmetic Operators

Used for performing basic math:

JavaScript Operators
Operator Description Example Result
+ Addition 5 + 2 7
- Subtraction 5 - 2 3
* Multiplication 5 * 2 10
/ Division 10 / 2 5
% Modulus (remainder) 5 % 2 1
** Exponentiation 2 ** 3 8
++ Increment x++ Adds 1
-- Decrement x-- Subtracts 1

2. Assignment Operators

Used to assign values to variables.

JavaScript Assignment Operators
Operator Example Same As
= x = 5 Assign 5 to x
+= x += 2 x = x + 2
-= x -= 2 x = x - 2
*= x *= 2 x = x * 2
/= x /= 2 x = x / 2
%= x %= 2 x = x % 2

3. Comparison Operators

Used to compare two values. These return a Boolean (true or false).


JavaScript Comparison Operators
Operator Description Example Result
== Equal (loose) 5 == "5" true
=== Equal (strict) 5 === "5" false
!= Not equal (loose) 5 != "5" false
!== Not equal (strict) 5 !== "5" true
> Greater than 6 > 3 true
<< /td> Less than 3 < 6 true
>= Greater than or equal to 5 >= 5 true
<=< /td> Less than or equal to 5 <= 4 false

4. Logical Operators

Used to combine multiple conditions.


JavaScript Logical Operators
Operator Description Example Result
&& Logical AND true && false false
|| Logical OR true || false true
! Logical NOT !true false

5. Type Operators


JavaScript Type Operators
Operator Description Example
typeof Returns the type of a variable typeof "hello" → "string"
instanceof Checks if object is an instance of a class obj instanceof Object

Bonus: String Concatenation

The + operator is also used to join strings:

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