PHP Basic
PHP HOME PHP Intro PHP Install PHP Syntax PHP Variables PHP String PHP Operators PHP If...Else PHP Switch PHP Arrays PHP Sorting Arrays PHP While Loops PHP For Loops PHP Functions PHP Forms PHP $_GET PHP $_POSTPHP Advanced
PHP Arrays Multi PHP Date PHP Include PHP File PHP File Upload PHP Cookies PHP Sessions PHP E-mail PHP Secure E-mail PHP Error PHP Exception PHP FilterPHP Database
PHP MySQL Intro PHP MySQL Connect PHP CREATE DB/Table PHP INSERT INTO PHP SELECT PHP WHERE PHP ORDER BY PHP UPDATE PHP DELETE PHP ODBCPHP XML
XML Expat Parser XML DOM XML SimpleXMLPHP and AJAX
AJAX Intro AJAX PHP AJAX Database AJAX XML AJAX Live Search AJAX RSS Reader AJAX PollPHP Reference
PHP Array PHP Calendar PHP Date PHP Directory PHP Error PHP Filesystem PHP Filter PHP FTP PHP HTTP PHP Libxml PHP Mail PHP Math PHP Misc PHP MySQLi PHP SimpleXML PHP String PHP XML PHP Zip PHP TimezonesPHP Quiz
PHP Quiz PHP CertificatePHP log() Function
Complete PHP Math Reference
Definition and Usage
The log() function returns the natural logarithm (base E) of a number.
Syntax
log(x,base)
| 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))
?>
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
0.69314718056
0
-1.#INF
-1.#IND
Complete PHP Math Reference
Your suggestion:
Close [X]
Thank You For Helping Us!
Your message has been sent to W3Schools.
Close [X]
