(PHP 4, PHP 5, PHP 7, PHP 8)
log — Natural logarithm
If the optional base parameter is specified,
log() returns logbase
num, otherwise log()
returns the natural logarithm of num.
numThe value to calculate the logarithm for
baseThe optional logarithmic base to use (defaults to 'e' and so to the natural logarithm).
The logarithm of num to
base, if given, or the
natural logarithm.