Perl log 函数
描述
This function returns the natural logarithm of EXPR, or $_ if omitted. To get the log of another base, use basic algebra: The base-N log of a number is equal to the natural log of that number divided by the natural log of N.
语法
以下是此函数的简单语法 −
log EXPR log
返回值
This function returns Floating point number in scalar context.
示例
以下是显示其基本用法的示例代码 −
#!/usr/bin/perl -w
print "log10(2): ", log10(2), "\n";
print "log10(2): ", log10(3), "\n";
print "log10(2): ", log10(5), "\n";
sub log10 {
my $n = shift;
return log($n)/log(10);
}
执行上述代码时，会产生以下结果 −
log10(2): 0.301029995663981 log10(2): 0.477121254719662 log10(2): 0.698970004336019
