java中的双数据类型与十进制值冲突[重复]

时间:2021-08-25 00:45:04

This question already has an answer here:

这个问题在这里已有答案:

I have a silly question. Why this is giving 488.15999999999997 instead of 488.16

我有一个愚蠢的问题。为什么这给了488.15999999999997而不是488.16

double dbl = 427.14 + 61.02;
System.out.println(dbl);

I heard that we must use BigDecimal if we are considering this much accuracy (like currency related logics). But I want to know what is behind this.

我听说如果我们考虑这么高的准确性(如货币相关逻辑),我们必须使用BigDecimal。但我想知道这背后是什么。

2 个解决方案

#1


1  

It's "normal" behavior. Remember, for the general case decimal values can not be represented exactly in a computer, so little errors will begin to creep. Take a look at What Every Computer Scientist Should Know About Floating-Point Arithmetic, it's mandatory reading for anyone writing code dealing with decimal values.

这是“正常”行为。请记住,对于一般情况,十进制值无法在计算机中准确表示,因此很少有错误会开始蔓延。看看每个计算机科学家应该知道的关于浮点运算的内容,对于任何编写处理十进制值的代码的人来说,它都是必读的。

#2


1  

How to resolve a Java Rounding Double issue This similar question's answer points here https://blogs.oracle.com/CoreJavaTechTips/entry/the_need_for_bigdecimal

如何解决Java Rounding Double问题这个类似问题的答案点在这里https://blogs.oracle.com/CoreJavaTechTips/entry/the_need_for_bigdecimal

#1


1  

It's "normal" behavior. Remember, for the general case decimal values can not be represented exactly in a computer, so little errors will begin to creep. Take a look at What Every Computer Scientist Should Know About Floating-Point Arithmetic, it's mandatory reading for anyone writing code dealing with decimal values.

这是“正常”行为。请记住,对于一般情况,十进制值无法在计算机中准确表示,因此很少有错误会开始蔓延。看看每个计算机科学家应该知道的关于浮点运算的内容,对于任何编写处理十进制值的代码的人来说,它都是必读的。

#2


1  

How to resolve a Java Rounding Double issue This similar question's answer points here https://blogs.oracle.com/CoreJavaTechTips/entry/the_need_for_bigdecimal

如何解决Java Rounding Double问题这个类似问题的答案点在这里https://blogs.oracle.com/CoreJavaTechTips/entry/the_need_for_bigdecimal