|
Back
Next
The JavaScript Math object allows us to perform common mathematical tasks such
as addition, subtraction, multiplication, division, etc..
The JavaScript Math object includes several mathematical values and functions.
We do not need to define the Math object before using it. Below JavaScript Math
object's syntax is the following
Syntax of JavaScript Math Object
<script type = "text/javascript">
Math.propertyname
//or:
Math.methodname(parameters)
</script>
JavaScript Math Methods
Although most of the methods used by Math are self-evident-such as using Math.sin to calculate the sine
function of a number-they are summarized in the following sections, with examples for your reference.
JavaScript Math Object Methods and Properties List
| JavaScript Math Object Method Name |
Example of JavaScript Math Object |
Returned Value of Math Object Examples
|
| abs |
Math.abs(-79)
|
79 |
| acos |
Math.acos(.5)
|
1.047197551196597 631 |
| asin |
Math.asin(1)
Math.ceil(7.6)
|
1.570796326794896 558
8 |
| cos |
Math.cos(.4)
|
0.9210609940028851 028 |
| atan |
Math.atan(.5)
|
0.4636476090008060 935 |
| ceil exp
|
Math.exp(8)
|
2980.957987041728 302 |
| floor |
Math.floor(8.9)
|
8 |
| log |
Math.log(5)
|
1.60943791243410 0282 |
| max |
Math.max(1, 700)
|
700 |
| min |
Math.min(1, 700)
|
1 |
| pow |
Math.pow(6,2)
|
36 |
| random
|
Math.random()
|
.7877896 (varies) |
| round |
Math.round(.567)
|
1 |
| sin |
Math.sin(Math.PI)
|
0 |
| sqrt |
Math.sqrt(9801)
|
99 |
| tan |
Math.tan(1.5*Math.PI)
|
INF (infinity) |
JavaScript Math.abs Method
document.write(Math.abs(-1));
//JavaScritp Math.abs returns the absolute value of its numeric argument.
//For example, the above will return 1
JavaScript acos, asin, atan, cos, sin, tan Math Methods
document.write(Math.acos(-1));
//JavaScript Math.acos, Math.asin, Math.atan, Math.cos, Math.sin, Math.tan.
//These return that trig function in radians.
//For example, the above will return 3.141592653589793116
JavaScript Math.ceil Method
document.write(Math.ceil(14.49999999));
//JavaScript Math.ceil returns the smallest integer
//greater than or equal to the argument passed to it.
//This is equivalent to always rounding up to the nearest integer.
//For example, the above example will return 15:
JavaScript Math.exp Method
document.write(Math.exp(5));
//JavaScript Math.exp returns the power of its argument.
//For example, the above Example will return 148.4131591025765999
JavaScript Math.floor Method
document.write(Math.floor(1.9999999));
//JavaScript Math.floor returns the greatest integer less than or
//equal to the value passed to it. This is equivalent to always
//rounding down to the nearest integer.
//For example, the above example will return 1
JavaScript Math.log Method
pie = Math.PI;
pielog = Math.log(pie);
document.write("The log to the base e of PI is: " + pielog + " .");
//JavaScript Math.log returns the natural log of the argument passed to it.
//For example, the above example will return the log to the base e of pi,
//which is 1.144729885849400164
JavaScript max, min Math Methods
with (Math) {
document.write("Between Euler's constant and
PI, " + max(E,PI) + " is greater.")
}
//JavaScript Math.max, Math.min.
//Given two numbers, max returns the greater of the two,
//and min returns the lesser of the two
JavaScript Math.pow Method
document.write(Math.pow(10,4));
//JavaScript Math.pow given a base and an exponent,
//this returns the base to the exponent power.
//For example, the above example return 10000
JavaScript Math.random Method
document.write(Math.random());
//below lines of random number generation in JavaScript
//will generate any number from 0 to 9
var ranNum= Math.floor(Math.random()*10);
document.write(ranNum);
//JavaScript Math.random method returns a pseudo-random number between 0 and 1.
//For example, the above example might return 0.09983341664682815475:
JavaScript Math.round Method
document.write(Math.round(1.4999999999));
//JavaScript Math.round method returns the argument rounded to
//the nearest integer. It rounds up if the fractional part of
//the number is .5 or greater, and down otherwise.
//For example, the above example will return 1
JavaScript Math.sqrt Method
document.write(Math.sqrt(144));
//JavaScript Math.sqrt returns the square root of its argument. The argument must
//be non-negative. otherwise, the sqrt method returns 0.
//For example, the following returns 12
JavaScript Math Properties
The JavaScript Math object provides us with a few constants that we can use for
various scientific and algebraic functions in JavaScript. Note that these
JavaScript Math properties are
constants and cannot be changed by JavaScript. The following is a summary with each
JavaScript Math property's approximate values.
- E
Euler's constant, the base of natural algorithms. Approximately 2.718.
- LN2
The natural log of 2. Approximately 0.693.
- LN10
The natural log of 10. Approximately 2.302.
- PI
The ratio of the circumference of a circle to its diameter.
Approximately 3.1416.
- SQRT1_2
The square root of .5 (one half) or one over the square root of 2.
Approximately 0.707.
- SQRT2
The square root of 2. Approximately 1.414.
JavaScript Math Object Properties List
| JavaScript Math Property Name |
Example of JavaScript Math Property |
Returned Value of JavaScript Math Property
|
| E |
Math.E*5
|
(2.718281828459045091)
13.59140914229522501
|
| LN10 |
Math.LN10/6
|
(2.302585092994045901)
0.3837641821656743168
|
| LN2 |
Math.LN2-Math.E
|
(0.69314718055994529)
-2.025134647899099694
|
| PI |
Math.sin(2*Math.PI/4)1
|
3.141592653589793116
|
| SQRT2 |
1/Math.SQRT2 |
0.7071067811865474617
|
Back
Next
| 
Home 