Core JavaScript 1.5 Reference:Global Objects:Math:log
From MDC
Contents |
[edit] Summary
Returns the natural logarithm (base E) of a number.
| Method of Math | |
|
Static |
|
| Implemented in: | JavaScript 1.0, NES 2.0 |
| ECMA Version: | ECMA-262 |
[edit] Syntax
Math.log(x)
[edit] Parameters
-
x - A number.
[edit] Description
If the value of number is negative, the return value is always NaN.
Because log is a static method of Math, you always use it as Math.log(), rather than as a method of a Math object you created.
[edit] Examples
[edit] Example: Using Math.log
The following function returns the natural log of the variable x:
function getLog(x) {
return Math.log(x)
}
If you pass getLog the value 10, it returns 2.302585092994046; if you pass it the value 0, it returns -Infinity; if you pass it the value -1, it returns NaN because -1 is out of range.