PHP: log() function

Last update on August 19 2022 21:50:40 (UTC/GMT +8 hours)

Description

The log() function returns the natural logarithm of a number.

Version:

(PHP 4 and above)

Syntax:

log(number,nbase)

Parameter:

Name	Description	Required / Optional	Type
number	The value to calculate the logarithm.	Required	Float
nbase	The base to use. Default is 'e'.	Optional	Float

Return value:

The logarithm of number to nbase, if given, or the natural logarithm.

Value Type: Float.

Example :

<?php
echo(log(2) . "<br />");
echo(log(1.234) . "<br />");
echo(log(0) . "<br />");
echo(log(1) . "<br />");
?>

Output :

0.69314718056
0.210260925483
-INF
0

See also

PHP Function Reference

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