从字符串创建正则表达式匹配模式

Question

Is there a way, using c# or vb, to take a string (in this case a phone number) and construct a regex match string from it, so that it also ignores spaces or other characters in there?

So a match would be found on all of these assuming the input string was 01789000111 :-

01789 000111 OR 01789 000 111 OR 01789 00 01 11 OR (01789) 000111

Answer 1

Remove the non-digits with a regex replace then compare:

var match = Regex.Replace(src, @"\D+", "") == target;

Alternatively, you could convert the target digits to a pattern and test:

var ans = Regex.IsMatch(src, Regex.Replace(target, @"\d", @"\D?$0\D?"))

If you are comparing a lot of src strings to the target, you should probably create a compiled Regex from the target:

var tpattern = new Regex(Regex.Replace(target, @"\d", @"\D?$0\D?"), RegexOptions.Compiled);

var ans = tpattern.IsMatch(src);