The JavaScript Math object allows you to perform mathematical tasks on numbers.
Example
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.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:
Example
Math.round(4.7); // returns 5
Math.round(4.4); // returns 4
Math.round(4.2); // returns 4
Math.round(-4.2); // returns -4
Math.ceil()
Math.ceil(x) returns the value of x rounded up to its nearest integer:
Example
Math.ceil(4.7); // returns 5
Math.ceil(4.4); // returns 5
Math.ceil(4.2); // returns 5
Math.ceil(-4.2); // returns -4
Math.floor()
Math.floor(x) returns the value of x rounded down to its nearest integer:
Example
Math.floor(4.7); // returns 4
Math.floor(4.4); // returns 4
Math.floor(4.2); // returns 4
Math.floor(-4.2); // returns -5
Math.trunc()
Math.trunc(x) returns the integer part of x:
Example
Math.trunc(4.7); // returns 4
Math.trunc(4.4); // returns 4
Math.trunc(4.2); // returns 4
Math.trunc(-4.2); // returns -4
Math.sign()
Math.sign(x) returns if x is negative, null or positive:
Example
Math.sign(0); // returns 0
Math.sign(4); // returns 1
Math.pow()
Math.pow(x, y) returns the value of x to the power of y:
Example
Math.sqrt()
Math.sqrt(x) returns the square root of x:
Example
Math.abs()
Math.abs(x) returns the absolute (positive) value of x:
Example
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.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.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
Example
Math.random()
Math.random() returns a random number between 0 (inclusive), and 1 (exclusive):
Example
The Math.log() Method
Math.log(x) returns the natural logarithm of x:
Example
The natural logarithm returns the time needed to reach a certain level of growth.
Math.E and Math.log() are twins.
How many times must we multiply Math.E to get 10?
Example
The Math.log2() Method
Math.log2(x) returns the base 2 logarithm of x.
How many times must we multiply 2 to get 8?
Example
The Math.log10() Method
Math.log10(x) returns the base 10 logarithm of x.
How many times must we multiply 10 to get 1000?
Example
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