The JavaScript Math object allows you to perform mathematical tasks on numbers.

Example

Math.PI;

 

The Math Object

Unlike other objects, the Math aobject 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);

 

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