The Math object allows you to perform common mathematical tasks.
The Math object allows you to perform common mathematical tasks.
The Math object includes several mathematical values and functions. You do not need to define the Math object before using it.
JavaScript provides eight mathematical values (constants) that can be accessed from the Math object. These are: E, PI, square root of 2, square root of 1/2, natural log of 2, natural log of 10, base-2 log of E, and base-10 log of E.
You may reference these values from your JavaScript like this:
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Math.E |
In addition to the mathematical values that can be accessed from the Math object there are also several functions (methods) available.
Examples of functions (methods):
The following example uses the round() method of the Math object to round a number to the nearest integer:
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document.write(Math.round(21.8)) |
The code above will result in the following output:
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22 |
The following example uses the random() method of the Math object to return a random number between 0 and 1:
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document.write(Math.random()) |
The code above can result in the following output:
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The following example uses the floor() and random() methods of the Math object to return a random number between 0 and 100:
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document.write(Math.floor(Math.random()*101)) |
The code above can result in the following output:
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Method |
Description |
| abs(x) | Returns the absolute value of a number |
| acos(x) | Returns the arccosine of a number |
| asin(x) | Returns the arcsine of a number |
| atan(x) | Returns the arctangent of x as a numeric value between -PI/2 and PI/2 radians |
| atan2(y,x) | Returns the angle theta of an (x,y) point as a numeric value between -PI and PI radians |
| ceil(x) | Returns the value of a number rounded upwards to the nearest integer |
| cos(x) | Returns the cosine of a number |
| exp(x) | Returns the value of Ex |
| floor(x) | Returns the value of a number rounded downwards to the nearest integer |
| log(x) | Returns the natural logarithm (base E) of a number |
| max(x,y) | Returns the number with the highest value of x and y |
| min(x,y) | Returns the number with the lowest value of x and y |
| 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 a number to the nearest integer |
| sin(x) | Returns the sine of a number |
| sqrt(x) | Returns the square root of a number |
| tan(x) | Returns the tangent of an angle |
| toSource() | Represents the source code of an object |
| valueOf() | Returns the primitive value of a Math object |
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Property |
Description |
| constructor | A reference to the function that created the object |
| E | Returns Euler's constant (approx. 2.718) |
| LN2 | Returns the natural logarithm of 2 (approx. 0.693) |
| LN10 | Returns the natural logarithm of 10 (approx. 2.302) |
| LOG2E | Returns the base-2 logarithm of E (approx. 1.442) |
| LOG10E | Returns the base-10 logarithm of E (approx. 0.434) |
| PI | Returns PI (approx. 3.14159) |
| prototype | Allows you to add properties and methods to the object |
| SQRT1_2 | Returns the square root of 1/2 (approx. 0.707) |
| SQRT2 | Returns the square root of 2 (approx. 1.414) |
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