JS Math

The Math Object

The JavaScript Math object allows you to perform mathematical tasks.

The Math object is static.

All methods and properties can be used without creating a Math object first.

Math.PI;

Math Properties (Constants)

The syntax for any Math property is : Math.property.

JavaScript provides 8 mathematical constants that can be accessed as Math properties:

Example

Math.E        // returns Euler's number

Math.PI       // returns PI

Math.SQRT2    // returns the square root of 2

Math.SQRT1_2  // returns the square root of 1/2

Math.LN2      // returns the natural logarithm of 2

Math.LN10     // returns the natural logarithm of 10

Math.LOG2E    // returns base 2 logarithm of E

Math.LOG10E   // returns base 10 logarithm of E

Math Methods

The syntax for Math any methods is : Math.method(number)

Number to Integer

There are 4 common methods to round a number to an integer:

Math.round()

Math.round(x) returns the nearest integer:

Examples

Math.round(4.6);

Math.ceil()

Math.ceil(x) returns the value of x rounded up to its nearest integer:

Example

Math.ceil(4.9);

Math.ceil(4.7);

Math.ceil(4.4);

Math.ceil(4.2);

Math.ceil(-4.2);

Math.floor()

Math.floor(x) returns the value of x rounded down to its nearest integer:

Example

Math.floor(4.9);

Math.floor(4.7);

Math.floor(4.4);

Math.floor(4.2);

Math.floor(-4.2);

Math.trunc()

Math.trunc(x) returns the integer part of x:

Example

Math.trunc(4.9);

Math.trunc(4.7);

Math.trunc(4.4);

Math.trunc(4.2);

Math.trunc(-4.2);

Math.sign()

Math.sign(x) returns if x is negative, null or positive.

• If x is positive it returns 1
• If x is negative it returns -1
• If x is zero, it returns 0

Example

Math.sign(-4);

Math.sign(0);

Math.sign(4);

Note: Math.trunc() and Math.sign() were added to JavaScript 2015 - ES6.

Math.pow()

Math.pow(x, y) returns the value of x to the power of y:

Example

Math.pow(8, 2);

Math.sqrt()

Math.sqrt(x) returns the square root of x:

Example

Math.sqrt(64);

Math.abs()

Math.abs(x) returns the absolute (positive) value of x:

Example

Math.abs(-4.7);

Math.sin()

Math.sin(x) returns the sine (a value between -1 and 1) of the angle x (given in radians).

If you want to use degrees instead of radians, you have to convert degrees to radians:

Angle in radians = Angle in degrees x PI / 180.

Example

Math.sin(90 * Math.PI / 180);     // returns 1 (the sine of 90 degrees)

Math.cos()

Math.cos(x) returns the cosine (a value between -1 and 1) of the angle x (given in radians).

If you want to use degrees instead of radians, you have to convert degrees to radians:

Angle in radians = Angle in degrees x PI / 180.

Example

Math.cos(0 * Math.PI / 180);     // returns 1 (the cos of 0 degrees)

Math.min() and Math.max()

Math.min() and Math.max() can be used to find the lowest or highest value in a list of arguments:

Example

Math.min(0, 150, 30, 20, -8, -200);

Example

Math.max(0, 150, 30, 20, -8, -200);

Math.random()

Math.random() returns a random number between 0 (inclusive), and 1 (exclusive):

Example

Math.random();

Note: You will learn more about Math.random() in the next chapter of this tutorial.

The Math.log() Method

Math.log(x) returns the natural logarithm of x.

The natural logarithm returns the time needed to reach a certain level of growth:

Examples

Math.log(1);

Math.E and Math.log() are twins.

Math.log(10);

The Math.log2() Method

Math.log2(x) returns the base 2 logarithm of x.

Math.log2(8);

The Math.log10() Method

Math.log10(x) returns the base 10 logarithm of x.

Math.log10(1000);

Note: Learn More: Full Math Reference