public class yuan {
static double C(double r){
return 3.14*r*r;
}
public static void main(String[] args) {
double a=3.14;
for(int i=1;i<30;i++){
System.out.println(i);
System.out.println(C(i));
System.out.println(a*i*i);
}
}
}
输出结果是1
3.14
3.14
2
12.56
12.56
3
28.259999999999998
28.259999999999998
4
50.24
50.24
5
78.5
78.5
6
113.03999999999999
113.03999999999999
7
153.86
153.86
8
200.96
200.96
9
254.34
254.34
10
314.0
314.0
11
379.94
379.94
12
452.15999999999997
452.15999999999997
13
530.66
530.66
14
615.44
615.44
15
706.5
706.5
16
803.84
803.84
17
907.46
907.46
18
1017.36
1017.36
19
1133.54
1133.54
20
1256.0
1256.0
21
1384.74
1384.74
22
1519.76
1519.76
23
1661.06
1661.06
24
1808.6399999999999
1808.6399999999999
25
1962.5
1962.5
26
2122.64
2122.64
27
2289.06
2289.06
28
2461.76
2461.76
29
2640.7400000000002
2640.7400000000002
请教大神们 为什么只有在 3 6 12 24 29 时候精度如此不同 小数点后面为什么这么多位???
谢谢