The JavaScript Math object allows you to perform mathematical tasks on numbers.
Example
Math.PI;
The Math Object
Unlike other objects, the Math object has no constructor.
The Math object is static.
All methods and properties can be used without creating a Math object first.
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(x) | Returns x rounded to its nearest integer |
| Math.ceil(x) | Returns x rounded up to its nearest integer |
| Math.floor(x) | Returns x rounded down to its nearest integer |
| Math.trunc(x) | Returns the integer part of x (new in ES6) |
Math.round()
Math.round(x) returns the nearest integer:
Examples
Math.round(4.6); Math.round(4.5); Math.round(4.4);
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:
Example
Math.sign(-4);
Math.sign(0);
Math.sign(4);
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();
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.log(2); Math.log(3);
Math.E and Math.log() are twins.
How many times must we multiply Math.E to get 10?
Math.log(10);
The Math.log2() Method
Math.log2(x) returns the base 2 logarithm of x.
How many times must we multiply 2 to get 8?
Math.log2(8);
The Math.log10() Method
Math.log10(x) returns the base 10 logarithm of x.
How many times must we multiply 10 to get 1000?
Math.log10(1000);
JavaScript Math Methods
| Method | Description |
|---|---|
| abs(x) | Returns the absolute value of x |
| acos(x) | Returns the arccosine of x, in radians |
| acosh(x) | Returns the hyperbolic arccosine of x |
| asin(x) | Returns the arcsine of x, in radians |
| asinh(x) | Returns the hyperbolic arcsine of x |
| atan(x) | Returns the arctangent of x as a numeric value between -PI/2 and PI/2 radians |
| atan2(y, x) | Returns the arctangent of the quotient of its arguments |
| atanh(x) | Returns the hyperbolic arctangent of x |
| cbrt(x) | Returns the cubic root of x |
| ceil(x) | Returns x, rounded upwards to the nearest integer |
| cos(x) | Returns the cosine of x (x is in radians) |
| cosh(x) | Returns the hyperbolic cosine of x |
| exp(x) | Returns the value of Ex |
| floor(x) | Returns x, rounded downwards to the nearest integer |
| log(x) | Returns the natural logarithm (base E) of x |
| max(x, y, z, …, n) | Returns the number with the highest value |
| min(x, y, z, …, n) | Returns the number with the lowest value |
| pow(x, y) | Returns the value of x to the power of y |
| random() | Returns a random number between 0 and 1 |
| round(x) | Rounds x to the nearest integer |
| sign(x) | Returns if x is negative, null or positive (-1, 0, 1) |
| sin(x) | Returns the sine of x (x is in radians) |
| sinh(x) | Returns the hyperbolic sine of x |
| sqrt(x) | Returns the square root of x |
| tan(x) | Returns the tangent of an angle |
| tanh(x) | Returns the hyperbolic tangent of a number |
| trunc(x) | Returns the integer part of a number (x) |