用于检查在文本框中输入的文本是否包含数字，逗号和连字符的正则表达式

Question

I have created a windows form, that has 2 columns of textboxes - Range of lines and Total number of lines. I want to have a check in the Range of lines textboxes to make sure that the data entered consists only of numbers, commas and hyphens in the correct format - that is, it can be something like : 10-20,30-40,50,60,70. But anything apart from this should not be allowed.

Basically I want to automatically fill up the "Total number of Lines" textbox with the data available in the "Range of lines" textbox. So in the above example, the count would be - (20 minus 10) + (40 minus 30) plus 1(for line 50) plus 1(for line 60) plus 1(for line 70) = 23.

I tried something like :

string reg = @"^([0-9]+([,][0-9]+))* |([0-9]+([.\–-][0-9]+))$";

But this validates a case like 10-20-30 also as correct. Which is not right according to my expecation.

Could you please help me here. Many thanks in advance.

Answer 1

The possible formats for each component are:

\d+-\d+
\d+

We can combine them since they share the same structure:

\d+(-\d+)?

The usual regex pattern for several things X that are separated by a separator is

X(,X)*

So from that we can build the final regex that has at least one of those components, separated by commas:

^\d+(-\d+)?(,\d+(-\d+)?)*$

Quick PowerShell test:

PS> '50,60','10-20','1,2-5,7','10-20,30-40,50,60,70','10-20-30' -match '^\d+(-\d+)?(,\d+(-\d+)?)*$'
50,60
10-20
1,2-5,7
10-20,30-40,50,60,70