英文:
How to force a float to get stored with two decimals (.00)
问题
我所需的：我需要在Java（11）中存储一个保留两位小数的浮点数。
我所做的：我使用了BigDecimal类，并没有出现问题，即使小数部分是.00，比例也如预期一样。
我的问题是什么：当我使用.floatValue()将BigDecimal转换为float时，如果小数部分是.00，它会去掉尾随的0。
一些示例
- 2.45（Big dec）被转换为浮点数2.45
- 2.00（Big dec）被转换为浮点数2.0 ==> 我希望是2.00
有解决方案吗？谢谢！
编辑：将浮点数作为字符串输出不是我想要的，我需要将变量存储为浮点数。
我快速检查了DecimalFormat，但目前我只找到了将其格式化为字符串的方法。
编辑2：我正在开发一个REST API，我想要返回一个JSON，其中必须将价格输出为浮点数（否则我会将其返回为BigDecimal）。我希望每次返回带有2位小数的价格。除了小数部分是.00（.01到.99的情况正常工作）的情况外，它在所有情况下都有效。JSON中的Float类型是我无法更改的约束。
英文:
What I need : I need to store a Float with two decimals in java (11)
What I did : I used the BigDecimal class with no problems, the scale is as expected even when the decimal portion is .00
What is my problem : When I convert the BigDecimal to a float with .floatValue() it removes the trailing 0 if the decimal portion is .00
A few examples
- 2.45 (Big dec) gets converted to 2.45 as a Float
- 2.00 (Big dec) gets converted to 2.0 as a Float ==> I want 2.00
Any solution ? Thanks !
EDIT : Outputting the float as a string is not what I want, I need to store the variable as a Float
I checked quickly DecimalFormat but at the moment I only found methods that format it as a string.
EDIT2 : I am working on a REST api, I want to return a JSON which has to output a price as a Float (else I would have returned it as a big decimal) I want to return the price with 2 decimals every time. It works in all cases except when the decimal portion is .00 (.01 to .99 works fine) as explained above. The Float type in the JSON is a constraint that I cannot change.
答案1
得分: 1
你无法存储带有两位小数的浮点数。这不是浮点数的工作方式。它们是数字的二进制表示，而不是十进制表示。
你可以将浮点数格式化为带有两位小数。
英文:
You can't store a float with two decimals. It's not how floats work. They're a binary representation of a number, not a decimal one.
You can format a float with two decimals.
通过集体智慧和协作来改善编程学习和解决问题的方式。致力于成为全球开发者共同参与的知识库，让每个人都能够通过互相帮助和分享经验来进步。
评论