Simple JavaScript Math Function Use randomly

2 min readNov 2, 2020

Math is a built-in object. It has properties and methods for mathematical constants and functions. It’s not a function object.

Math works with the number type. It doesn't work with BigInt.

Unlike many other global objects, Math is not a constructor. All properties and methods of Math are static. You refer to the constant pi as Math.PI and you call the cosine function as Math.cos(x), where x is the method’s argument. Constants are defined with the full precision of real numbers in JavaScript.

Math.abs()

abs() is a static method of Math, you always use it as Math.abs(), rather than as a method of a Math object created.

Behavior of abs() :

Math.abs(‘-1’); // 1

Math.abs(-2); // 2

Math.abs(null); // 0

Math.abs(‘’); // 0

Math.abs([]); // 0

Math.abs([2]); // 2

Math.abs([1,2]); // NaN

Math.abs({}); // NaN

Math.abs(‘string’); // NaN

Math.abs(); // NaN

Math.floor()

floor() is a static method of Math, you always use it as Math.floor(), rather than as a method of a Math object created

Behavior of floor() :

var a = Math.floor(0.60); //0
var b = Math.floor(0.40); //0
var c = Math.floor(5); //5
var d = Math.floor(5.1); //5
var e = Math.floor(-5.1); //-6
var f = Math.floor(-5.9); //-6

`Math.ceil()`

ceil() is a static method of Math, you always use it as Math.ceil(), rather than as a method of a Math object created

Behavior of ceil() :

Math.ceil(.95); // 1

Math.ceil(4); // 4

Math.ceil(7.004); // 8

Math.ceil(-0.95); // -0

Math.ceil(-4); // -4

Math.ceil(-7.004); // -7

Math.random();

Return a random number between 0 (inclusive) and 1 (exclusive).

Behavior of random() :

Return a random number between 1 and 10:

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

Return a random number between 1 and 100:

Math.floor((Math.random() * 100) + 1);

Math.round()

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

Behavior of round():

var a = Math.round(2.60); // 3

var b = Math.round(2.50); // 3

var c = Math.round(2.49); //2

var d = Math.round(-2.60); //-3

var e = Math.round(-2.50); //-2

var f = Math.round(-2.49); //-2