BigDecimal如何比较大小

BigDecimal比较大小

这个类是java里精确计算的类，下面说一下两个BigDecimal对象大小，相等的判断

1 比较对象是否相等

一般的对象用equals，但是BigDecimal比较特殊，举个例子：

BigDecimal a=BigDecimal.valueOf(1.0);

BigDecimal b=BigDecimal.valueOf(1.000);

在现实中这两个数字是相等的，但是如果用

a.equals(b)结果是false;怎么不相等了呢？因为equals是比较内容，“1.0”和“1.000”当然不一样了

解决办法：

if(a.compareTo(b)==0) 结果是true

public static void main(String[] args) {
        BigDecimal a = BigDecimal.valueOf(1.0);
        BigDecimal b = BigDecimal.valueOf(1.000);
        if (a.compareTo(BigDecimal.ZERO) == 1) {//结果是true
            System.out.println("1");
        } else {
            System.out.println("2");
        }
    }

public int compareTo(BigDecimal val)

Compares this BigDecimal with the specified BigDecimal.

Two BigDecimal objects that are equal in value but have a different

scale (like 2.0 and 2.00) are considered equal by this method.

This method is provided in preference to individual methods for each of

the six boolean comparison operators (<, ==, >, >=, !=, <=).

The suggested idiom for performing these comparisons is: (x.compareTo(y) <op> 0), where <op> is one of the six comparison operators.

Specified by:

compareTo in interface Comparable<BigDecimal>

Parameters:

val - BigDecimal to which this BigDecimal is to be compared.

Returns:

-1, 0, or 1 as this BigDecimal is numerically less than, equal to, or greater than val.

简单翻译：

结果是

-1 小于

0 等于

1 大于