JavaScript Math & Math Reference — Interview Questions & Answers

Ques: What is the Math object in JavaScript?

Ans: The Math object in JavaScript is a built-in static object that provides mathematical constants and methods for performing numeric calculations like rounding, trigonometry, logarithms, random numbers, etc.

Example:

console.log(Math.PI);       // 3.141592653589793
console.log(Math.sqrt(25)); // 5

Ques: What are the features of the Math object?

Contains static methods (no need to create an instance)
Provides mathematical constants (PI, E, etc.)
Used for rounding, powers, roots, min/max, etc.
Supports random number generation

Ques: How do you get the value of π (pi)?

Math.PI;  // 3.141592653589793

Ques: How do you round numbers in JavaScript?

Method	Description	Example	Result
`Math.round(x)`	Rounds to nearest integer	`Math.round(4.6)`	`5`
`Math.floor(x)`	Rounds down	`Math.floor(4.9)`	`4`
`Math.ceil(x)`	Rounds up	`Math.ceil(4.1)`	`5`
`Math.trunc(x)`	Removes decimal part	`Math.trunc(4.8)`	`4`

Ques: What is the difference between Math.floor() and Math.trunc()?

Function	Description	Example
`Math.floor()`	Always rounds down	`Math.floor(-4.2)` → `-5`
`Math.trunc()`	Removes decimal part	`Math.trunc(-4.2)` → `-4`

Ques: How do you get the absolute value of a number?

Ans: Returns the non-negative value of a number.

Math.abs(-7); // 7

Ques: How to get the maximum or minimum of several numbers?

Math.max(4, 9, 2); // 9
Math.min(4, 9, 2); // 2

You can also use the spread operator:

let nums = [10, 25, 5];
Math.max(...nums); // 25

Ques: How to generate a random number in JavaScript?

Math.random(); // Returns a number between 0 (inclusive) and 1 (exclusive)

Example: Generate a random number between 1 and 10:

Math.floor(Math.random() * 10) + 1;

Ques: How to find the square root of a number?

Math.sqrt(49); // 7

Ques: How to calculate powers and exponents?

Math.pow(2, 3); // 8
// or modern syntax:
2 ** 3; // 8

Ques: How do you find the cube root or nth root of a number?

Math.cbrt(27); // 3
Math.pow(16, 1/4); // 4th root = 2

Ques: What are trigonometric methods in Math?

Method	Description	Example
`Math.sin(x)`	Returns sine (in radians)	`Math.sin(Math.PI/2)` → `1`
`Math.cos(x)`	Returns cosine	`Math.cos(0)` → `1`
`Math.tan(x)`	Returns tangent	`Math.tan(Math.PI/4)` → `1`

Inverse trigonometric functions:

Math.asin(x)
Math.acos(x)
Math.atan(x)

Ques: What are logarithmic and exponential functions in Math?

Method	Description	Example
`Math.log(x)`	Natural log (base e)	`Math.log(Math.E)` → `1`
`Math.log10(x)`	Base-10 log	`Math.log10(100)` → `2`
`Math.exp(x)`	e raised to power x	`Math.exp(1)` → `2.718...`

Ques: How to find the sign of a number?

Math.sign(7);   // 1
Math.sign(-5);  // -1
Math.sign(0);   // 0

Ques: How to work with degrees instead of radians in trigonometric functions?

Ans: JavaScript trigonometric functions use radians, not degrees.

Convert degrees to radians:

function degToRad(deg) {
  return deg * (Math.PI / 180);
}
console.log(Math.sin(degToRad(90))); // 1

Ques: How to generate a random integer within a specific range?

function getRandomInt(min, max) {
  return Math.floor(Math.random() * (max - min + 1)) + min;
}

getRandomInt(1, 100); // returns random integer between 1 and 100

Ques: What constants are available in the Math object?

Constant	Value	Description
`Math.E`	2.718	Euler’s number
`Math.PI`	3.14159	Pi
`Math.SQRT2`	1.414	√2
`Math.SQRT1_2`	0.707	√(1/2)
`Math.LN2`	0.693	ln(2)
`Math.LN10`	2.303	ln(10)
`Math.LOG2E`	1.442	log₂(e)
`Math.LOG10E`	0.434	log₁₀(e)

Ques: What does Math.hypot() do?

Ans: Returns the square root of the sum of squares of arguments (useful for distance calculations).

Math.hypot(3, 4); // 5

Ques: What is the use of Math.clz32()?

Ans: Returns the number of leading zero bits in the 32-bit binary representation of a number.

Math.clz32(1); // 31
Math.clz32(1000); // 22

Ques: Is Math mutable or static?

Ans: Math is a static object, meaning:

You can’t instantiate it using new Math().
You can’t modify its properties or constants.

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