JSP基础问题加法和四舍五入

Question

double a = 12.236;                        
a = Math.round(a*Math.pow(10,2));    
a = a/Math.pow(10,2);                     
System.out.println(a);                    

Answer 1

import java.math.*;class A{
public static void main(String[] args){

double a = 12.236;                        
BigDecimal bd=new BigDecimal(a);                   
System.out.println(bd.setScale(2,BigDecimal.ROUND_HALF_UP));  
} 
}

Answer 2

double a
double b
 b=a*100+0.5
a=round(b)/100

Answer 3

你仔细研究一下math包吧，那里可以帮你解决这个问题

Answer 4

double a = 12.236;                        
a = Math.round(a*100);    
a = a/100;                     
System.out.println(a);