javascript - 美元金额的上限
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javascript - ceiling of a dollar amount
提问by bmarti44
So I am adding and subtracting floats in javascript, and I need to know how to always take the ceiling of any number that has more than 3 decimal places. For example:
所以我在 javascript 中添加和减去浮点数，我需要知道如何总是取任何超过 3 个小数位的数字的上限。例如：
3.19 = 3.19
3.19 = 3.19
3.191 = 3.20
3.191 = 3.20
3.00000001 = 3.01
3.00000001 = 3.01
回答by David Tang
num = Math.ceil(num * 100) / 100;
Though, due to the way floats are represented, you may not get a clean number that's to two decimal places. For display purposes, always do num.toFixed(2).
但是，由于浮点数的表示方式，您可能无法得到精确到小数点后两位的数字。出于显示目的，请始终执行num.toFixed(2).
回答by Amnon
Actually I don't think you want to represent dollar amounts as float, due to the same reason cited by Box9. For example, 0.1*3 != 0.3 in my browser. It's better to represent them as integers (e.g. cents).
实际上，由于 Box9 引用的相同原因，我认为您不想将美元金额表示为浮动金额。例如，0.1*3 != 0.3 在我的浏览器中。最好将它们表示为整数（例如美分）。
