Javascript Operators The Basic You need to Know :

Understanding Operators in JavaScript

While writing programs, we frequently perform operations on different values.

For example:

• Adding two numbers

• Comparing values

• Updating a variable’s value

• Combining multiple conditions

In JavaScript, the symbols used to perform these operations are called operators.

Operators are extremely important because they appear in almost every program we write.

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1. What Are Operators?

An operator is a symbol that performs an operation on values.

The values on which the operator works are called operands.

Example:

let total = 7 + 3

Here:

• 7 and 3 → operands

• + → operator

The + symbol tells JavaScript to add the two numbers together.

Operators allow programs to perform calculations, compare values, and control program logic.

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2. Arithmetic Operators

Arithmetic operators are used to perform mathematical calculations.

These operations are similar to the basic math we use daily.

Operator	Purpose
+	Addition
-	Subtraction
*	Multiplication
/	Division
%	Modulus (remainder)

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Addition (+)

The addition operator adds two numbers.

Example:

let x = 12
let y = 8

console.log(x + y)

Output:

20

The + operator is widely used in programming.

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Subtraction (-)

The subtraction operator finds the difference between two numbers.

Example:

let x = 15
let y = 6

console.log(x - y)

Output:

9

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Multiplication (*)

Multiplication is used to multiply numbers.

Example:

let x = 5
let y = 7

console.log(x * y)

Output:

35

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Division (/)

Division splits one number by another.

Example:

let x = 30
let y = 6

console.log(x / y)

Output:

5

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Modulus (%)

The modulus operator gives the remainder after division.

Example:

let x = 11
let y = 4

console.log(x % y)

Output:

3

Explanation:

11 ÷ 4 = 2 remainder 3

Practical Example

This operator is often used to check whether a number is even or odd.

let value = 12

console.log(value % 2)

Output:

0

If the remainder is 0, the number is even.

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3. Comparison Operators

Comparison operators are used to compare two values.

They return a boolean value, which can be:

• true

• false

Operator	Meaning
==	Equal (loose comparison)
===	Strict equality
!=	Not equal
>	Greater than
<	Less than

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Equal To (==)

The == operator checks whether two values are equal after converting their types if necessary.

Example:

console.log(8 == "8")

Output:

true

Why?

JavaScript converts the string "8" into the number 8 before comparing.

8 == "8"
8 == 8
true

Because of this automatic conversion, == can sometimes produce unexpected results.

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Strict Equal (===)

The === operator checks both the value and the data type.

Example:

console.log(8 === "8")

Output:

false

Explanation:

• 8 → number

• "8" → string

Since the data types are different, the result becomes false.

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Difference Between and =

Example:

console.log(20 == "20")
console.log(20 === "20")

Output:

true
false

Operator	What it checks
==	Value only
===	Value and type

Best Practice

In modern JavaScript, developers usually prefer using === because it avoids unexpected type conversions.

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Not Equal (!=)

This operator checks if two values are different.

Example:

console.log(7 != 4)

Output:

true

Because 7 and 4 are not equal.

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Greater Than (>) and Less Than (<)

These operators compare numbers.

Example:

console.log(18 > 10)

Output:

true

Another example:

console.log(3 < 1)

Output:

false

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4. Logical Operators

Logical operators are used when working with multiple conditions together.

They are commonly used in decision-making statements like if conditions.

Operator	Meaning
&&	Logical AND
!	Logical NOT

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Logical AND (&&)

The AND operator returns true only if both conditions are true.

Example:

let temperature = 25
let isSunny = true

console.log(temperature > 20 && isSunny)

Output:

true

Explanation:

• temperature > 20 → true

• isSunny → true

Both conditions are true, so the final result is true.

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Logical OR (||)

The OR operator returns true if at least one condition is true.

Example:

let hasCoupon = false
let isMember = true

console.log(hasCoupon || isMember)

Output:

true

Since one condition is true, the result becomes true.

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Logical NOT (!)

The NOT operator simply reverses a boolean value.

Example:

let isOnline = true

console.log(!isOnline)

Output:

false

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5. Assignment Operators

Assignment operators are used to assign values to variables.

The most basic assignment operator is:

=

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Basic Assignment (=)

Example:

let points = 50

Here the value 50 is assigned to the variable points.

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Addition Assignment (+=)

This operator adds a value to the variable and updates it.

Example:

let points = 10

points += 3

This is the same as writing:

points = points + 3

Final value:

13

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Subtraction Assignment (-=)

This operator subtracts a value from a variable and updates it.

Example:

let points = 25

points -= 5

Equivalent to:

points = points - 5

Final value:

20

These shorthand operators make the code shorter and easier to read.