java取某小数后N位，经典小例子

import java.util.*;

class  MathDemo
{
public static void main(String[] args)
{
saveTwo(12.3456,2,true);//12.34
}

public static void saveTwo(double d,int scale,boolean isRound)
{
//需要注意base的取值类型为double
double base = Math.pow(10,scale);
double num = isRound?Math.round(d*base)/base:((int)(d*base))/base;

sop("num="+num);
}
public static void sop(Object obj)
{

System.out.println(obj);
}
}