PHP - log() Function
The PHP log() function is used to return the natural logarithm or logarithm to the specified base of a given number.
Syntax
log(number, base)
Parameters
number |
Required. Specify the number. |
base |
Optional. Specify the base. Default is e |
Return Value
Returns the natural logarithm or logarithm to the specified base of a given number.
Example:
In the below example, log() function is used to calculate the natural logarithm and logarithm to the specified base of a given number.
<?php $x = 10; $y = 50; $z = 100; //calculate natural logarithm echo "log($x) equal to: ".log($x)."\n"; echo "log($y) equal to: ".log($y)."\n"; echo "log($z) equal to: ".log($z)."\n"; echo "\n"; //calculate base-10 logarithm echo "log($x, 10) equal to: ".log($x, 10)."\n"; echo "log($y, 10) equal to: ".log($y, 10)."\n"; echo "log($z, 10) equal to: ".log($z, 10)."\n"; ?>
The output of the above code will be:
log(10) equal to: 2.302585092994 log(50) equal to: 3.9120230054281 log(100) equal to: 4.6051701859881 log(10, 10) equal to: 1 log(50, 10) equal to: 1.698970004336 log(100, 10) equal to: 2
❮ PHP Math Functions