FilesExpand file tree

 master

/

Arith.java

Copy path

Blame

More file actions

Blame

More file actions

Latest commit

 

History

History

History

60 lines (59 loc) · 1.64 KB

 master

/

Arith.java

Copy path

Top

File metadata and controls

• Code
• Blame

60 lines (59 loc) · 1.64 KB

Raw

Copy raw file

Download raw file

Open symbols panel

Edit and raw actions

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

32

33

34

35

36

37

38

39

40

41

42

43

44

45

46

47

48

49

50

51

52

53

54

55

56

57

58

59

60

import java.math.*;

/**

* Description:

* <br/>网站: <a href="http://www.crazyit.org">疯狂Java联盟</a>

* <br/>Copyright (C), 2001-2016, Yeeku.H.Lee

* <br/>This program is protected by copyright laws.

* <br/>Program Name:

* <br/>Date:

* @author Yeeku.H.Lee kongyeeku@163.com

* @version 1.0

*/

public class Arith

{

// 默认除法运算精度

private static final int DEF_DIV_SCALE = 10;

// 构造器私有，让这个类不能实例化

private Arith() {}

// 提供精确的加法运算。

public static double add(double v1,double v2)

{

BigDecimal b1 = BigDecimal.valueOf(v1);

BigDecimal b2 = BigDecimal.valueOf(v2);

return b1.add(b2).doubleValue();

}

// 提供精确的减法运算。

public static double sub(double v1,double v2)

{

BigDecimal b1 = BigDecimal.valueOf(v1);

BigDecimal b2 = BigDecimal.valueOf(v2);

return b1.subtract(b2).doubleValue();

}

// 提供精确的乘法运算。

public static double mul(double v1,double v2)

{

BigDecimal b1 = BigDecimal.valueOf(v1);

BigDecimal b2 = BigDecimal.valueOf(v2);

return b1.multiply(b2).doubleValue();

}

// 提供（相对）精确的除法运算，当发生除不尽的情况时.

// 精确到小数点以后10位的数字四舍五入。

public static double div(double v1,double v2)

{

BigDecimal b1 = BigDecimal.valueOf(v1);

BigDecimal b2 = BigDecimal.valueOf(v2);

return b1.divide(b2 , DEF_DIV_SCALE

, BigDecimal.ROUND_HALF_UP).doubleValue();

}

public static void main(String[] args)

{

System.out.println("0.05 + 0.01 = "

+ Arith.add(0.05 , 0.01));

System.out.println("1.0 - 0.42 = "

+ Arith.sub(1.0 , 0.42));

System.out.println("4.015 * 100 = "

+ Arith.mul(4.015 , 100));

System.out.println("123.3 / 100 = "

+ Arith.div(123.3 , 100));

}

}