PHP log() function
 Complete PHP Math Reference
Definition and Usage
The log() function returns the natural logarithm (base E) of a number.
Syntax
| Parameter |
Description |
| x |
Required. A number |
| base |
Optional. If the base parameter is specified, log() returns
logbase x.
Note: The base parameter became available in PHP 4. |
Tips and Notes
Note: If the parameter x is negative, -1.#IND is returned.
Example
In the following example we will use the log() function on different numbers:
<?php
echo(log(2.7183) . "<br />");
echo(log(2) . "<br />");
echo(log(1) . "<br />");
echo(log(0) . "<br />");
echo(log(-1))
?>
|
The output of the code above will be:
1.00000668491
0.69314718056
0
-1.#INF
-1.#IND
|
Complete PHP Math Reference
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