C# 十进制值的正则表达式
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Regular Expression For Decimal Value
提问by Maverick
I want a regular expression for decimal input, which can take 4 digits before decimal or comma and 2 digits after decimal/comma. 5 digit number without decimal is invalid. Also can accept null.
我想要一个十进制输入的正则表达式，它可以在小数点或逗号之前取 4 位数字，在小数点/逗号之后取 2 位数字。不带小数的 5 位数字无效。也可以接受空值。
Correct Values can be:
正确的值可以是：
1, 1111, 2222.56, 0.99, 9999.5
1、1111、2222.56、0.99、9999.5
Invalid
无效的
88888, 8.888,
88888, 8.888,
Validation show also include comma along with decimal.
验证显示还包括逗号和小数点。
If possible, then also explain the expression.
如果可能，还要解释表达式。
采纳答案by Ria
Regex.IsMatch(strInput, @"[\d]{1,4}([.,][\d]{1,2})?");
and explain:
并解释：
[\d]{1,4} any character of: digits (0-9) between 1 and 4 times
[.,] any character of: '.', ','
[\d]{1,2} any character of: digits (0-9) between 1 and 2 times
(...)? match the expression or not (zero or one)
回答by Jirka Hanika
[0-9]{1,4}(\.[0-9]{1,2})?
This means, 1 to 4 digits, and then optionally both a decimal point and 1 to 2 digits.
这意味着，1 到 4 位数字，然后是可选的小数点和 1 到 2 位数字。
回答by burning_LEGION
use this regex \d{4}[,\.]\d{2}or \d+([,\.]\d+)?for any decimal
使用此正则表达式\d{4}[,\.]\d{2}或\d+([,\.]\d+)?任何小数
回答by Seenivasan
We can do code for checking Stirng value contains Decimal points by following code
我们可以通过以下代码来做检查Stirng值是否包含小数点的代码
Dim Success As Boolean
If text.Contains(".") Then
Dim result As Integer = Split(text, ".")(1)
If result > 0 Then
Success = True 'Containing Decimal Points greater than
Else
Success = False 'Containing "0" as Decimal Points
End If
End If
Return Success
回答by JacekT
^-?(0|[1-9]\d{0,3})([,\.]\d{1,2})?$
BEFORE COMMA:
逗号前：
^ - beginning of the string
^ - 字符串的开头
-? - there may be zero or one negative sign
-？- 可能有零或一个负号
0 - decimal may starts with only single zero at the beginning...
0 - 十进制可以只以一个零开头...
| - or ...
| - 或者 ...
[1-9] - with any digit from 1 to 9
[1-9] - 1 到 9 之间的任何数字
\d{0,3} - followed by any 3 digits
\d{0,3} - 后跟任意 3 位数字
AFTER COMMA:
逗号后：
[,.] - there may be "," or "."
[,.] - 可能有“,”或“.”
\d{1,2} - followed by 1 or 2 digits
\d{1,2} - 后跟 1 或 2 位数字
(...)? - zero or one time
（……）？- 零次或一次
$ - end of the string
$ - 字符串的结尾
