java中雙除10

Question

import java.util.*; 
public class test { 
    public static void main(String [] args) { 
     Scanner scn = new Scanner(System.in); 
     double s = 253.3; 
     while(s > 9) { 
      s = s/10; 
     } 
     System.out.println(s); 
    } 
} 

爲什麼輸出是2.5330000000000004而不是2.533？

Answer 1

因爲浮點值是一個近似值。

http://en.wikipedia.org/wiki/Floating_point