log

(PHP 4, PHP 5, PHP 7, PHP 8)

log —Natural logarithm

Description

If the optionalbase parameter is specified,log() returns log_basenum, otherwiselog() returns the natural logarithm ofnum.

Parameters

num

The value to calculate the logarithm for

base

The optional logarithmic base to use (defaults to 'e' and so to the natural logarithm).

Return Values

The logarithm ofnum tobase, if given, or the natural logarithm.

See Also

• log10() - Base-10 logarithm
• exp() - Calculates the exponent of e
• pow() - Exponential expression
• error_log() - Send an error message to the defined error handling routines