Math Object

Math is a built-in JavaScript object that provides a collection of properties and methods related to mathematical operations.

Examples:

console.log(Math.PI) // 3.141592653589793
console.log(Math.E)  // 2.718281828459045

📐 Math Methods

1. round() method

The Math.round() method rounds a decimal number to the nearest integer.

console.log(Math.round(3.4)) // 3
console.log(Math.round(3.7)) // 4

2. floor() method

The Math.floor() method rounds a number down to the greatest integer less than or equal to the given number.

console.log(Math.floor(3.9))  // 3
console.log(Math.floor(-3.2)) // -4

3. ceil() method

The Math.ceil() method rounds a number up to the smallest integer greater than or equal to the given number.

console.log(Math.ceil(3.22)) // 4
console.log(Math.ceil(3.8))  // 4

4. trunc() method

The Math.trunc() method removes all decimal places and keeps only the integer part of the number.

console.log(Math.trunc(3.88))  // 3
console.log(Math.trunc(-3.88)) // -3

5. abs() method

The Math.abs() method returns the absolute (non-negative) value of a number. It is similar to the modulus operation.

console.log(Math.abs(-2.03)) // 2.03
console.log(Math.abs(5))     // 5

6. pow() and sqrt() methods

• Math.pow() returns a number raised to a specified power.
• Math.sqrt() returns the square root of a number.

console.log(Math.pow(2, 3)) // 8

console.log(Math.sqrt(81)) // 9

7. log() method

The Math.log() method returns the natural logarithm of a number, that is, the logarithm to base e (approximately 2.718).

console.log(Math.log(10)) // 2.302585...

8. Trigonometric functions

JavaScript provides trigonometric functions through the Math object.

console.log(Math.sin(0)) // 0

console.log(Math.cos(0)) // 1

console.log(Math.tan(0)) // 0

Note

Trigonometric functions accept angles in radians, not degrees.

9. sign() method

The Math.sign() method returns:

• -1 for negative numbers.
• 1 for positive numbers.
• 0 for zero.

console.log(Math.sign(-9)) // -1
console.log(Math.sign(0))  // 0
console.log(Math.sign(9))  // 1

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Note

You can assign numbers to variables and pass those variables to Math methods instead of passing numbers directly.

let num = 3.8;

console.log(Math.round(num)) // 4
console.log(Math.floor(num)) // 3

Quick Revision Table

Method	Purpose
Math.round()	Rounds to nearest integer
Math.floor()	Rounds down
Math.ceil()	Rounds up
Math.trunc()	Removes decimal part
Math.abs()	Returns absolute value
Math.pow()	Calculates power
Math.sqrt()	Calculates square root
Math.log()	Returns natural logarithm
Math.sin()	Calculates sine
Math.cos()	Calculates cosine
Math.tan()	Calculates tangent
Math.sign()	Returns sign of a number