JavaScript JavaScript Math Object
Math
Object Methods
Method Description
abs(x) Returns the absolute value of x
acos(x) Returns the arccosine of x, in radians
asin(x) Returns the arcsine of x, in radians
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
ceil(x) Returns the value of x rounded up to its
nearest integer
cos(x) Returns the cosine of x (x is in radians)
exp(x) Returns the value of Ex
floor(x) Returns the value of x rounded down to its
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) Returns the value of x rounded to its nearest
integer
sin(x) Returns the sine of x (x is in radians)
sqrt(x) Returns the square root of x
tan(x) Returns the tangent of an angle
The
JavaScript Math object allows you to perform mathematical tasks on numbers.
Example
Math.PI; // returns 3.141592653589793
»
Math.round()
Math.round(x)
returns the value of x rounded to its nearest integer:
Example
Math.round(4.7); // returns 5
Math.round(4.4); // returns 4
»
Math.pow()
Math.pow(x,
y) returns the value of x to the power of y:
Example
Math.pow(8,
2); // returns 64
»
Math.sqrt()
Math.sqrt(x)
returns the square root of x:
Example
Math.sqrt(64); // returns 8
»
Math.abs()
Math.abs(x)
returns the absolute (positive) value of x:
Example
Math.abs(-4.7); // returns 4.7
»
Math.ceil()
Math.ceil(x)
returns the value of x rounded up to its nearest integer:
Example
Math.ceil(4.4); // returns 5
»
Math.floor()
Math.floor(x)
returns the value of x rounded down to its nearest integer:
Example
Math.floor(4.7); // returns 4
»
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); // returns -200
»
Example
Math.max(0,
150, 30, 20, -8, -200); // returns 150
»
Math.random()
Math.random()
returns a random number between 0 (inclusive),
and 1 (exclusive):
Example
Math.random(); // returns a random number
»
You will
learn more about Math.random() in the next chapter of this tutorial.
Math
Properties (Constants)
JavaScript
provides 8 mathematical constants that can be accessed with the Math object:
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
Constructor
Unlike other
global objects, the Math object has no constructor. Methods and properties are
static.
All methods
and properties (constants) can be used without creating a Math object first.
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