正则表达式问题 C#

Question

 const string strRegex =
    @"(?<city_country>[^.]+) (cca|ca.|ungefähr) (?<price>[\d.,]+) (eur)?";
 searchQuery = RemoveSpacesFromString(searchQuery);
 Regex regex = new Regex(strRegex, RegexOptions.IgnoreCase);

 Match m = regex.Match(searchQuery);
 ComplexAdvertismentsQuery query = new ComplexAdvertismentsQuery();

 if (m.Success)

while "Agadir ca. 600" is false but "Agadir ca. 600 eur" is true. "eur" is optional but "Agadir ca. 600" is false? Why?

Answer 1

Enclose eur in parenthesis, like so (eur)? .

? matches the preceding character zero or one times. By enclosing it in the parens, it will match the whole word.

Also, maybe it is matching the last space before (eur)? . Try this:

@"(?<city_country>[^.]+) (cca|ca.|ungefähr) (?<price>[\d.,]+)(\seur)?"

Notice, I removed the last white space and added \s , which matches any white space including space, tab, form-feed, etc.

Answer 2

I think you should write (eur)? instead of eur? . Ie place the Spacebefore also inside the parenthesis

Answer 3

Using (eur)? instead of eur? should solve the problem.

best way would be @"(?<city_country>[^.]+) (cca|ca.|ungefähr) (?<price>[\d.,]+)\s*(\seur)?") putting space only inside like ( eur) would not match something like "Agadir ca. 600 "

Answer 4

@"(?<city_country>[^.]+) (cca|ca.|ungefähr) (?<price>[\d.,]+)( eur)?"

OR

@"(?<city_country>[^.]+) (cca|ca.|ungefähr) (?<price>[\d.,]+)(\seur)?"