C# 中值 20 000 000,50 的数据类型？

Question

If I need to present value that is

20 000 000,50
12 000 000
 2 000 000,75
   100 000,866
18 000 000,42

What datatype for C# should I use?

Answer 1

So you're working with floating point values. You have two options:

1. Double
2. Decimal

Use Double if you are given significant digits , eg 2000000.50 actually means, say, 2.00e6 (3 significant digits). Usuallly these kinds of values are from physical world: volts , ampers , meters , etc.

Use Decimal if you are given significant digits after decimal point , eg 2000000.50 actually means 2000000.500 (3 digits after the decimal point ). Usually these kinds of values are from finance: dollars and cents etc.

Answer 2

You should use decimal.

Here is the description of decimal in MSDN:

https://msdn.microsoft.com/en-us/library/364x0z75.aspx

Here is the difference from double:

https://social.msdn.microsoft.com/Forums/vstudio/en-US/921a8ffc-9829-4145-bdc9-a96c1ec174a5/decimal-vs-double-difference?forum=csharpgeneral

Answer 3

The short answer is: decimal .

The alternative - double is not preferred for monetary values because the cents are binary encoded and frequently the values are rounded (eg instead of 100.04 you may have 100.03999999 ).

Answer 4

We used decimal too.

decimal = 128-bit precise decimal values with 28-29 significant digits,
double = 64-bit double-precision floating point type,
float = 32-bit single-precision floating point type,
int = 32-bit signed integer type