Regex to Match Specific Currency Formats in C# - implementing Edge Cases
Quick question that's been bugging me - I tried several approaches but none seem to work..... I'm sure I'm missing something obvious here, but I'm trying to create a regex pattern in C# to match currency formats, specifically those that can handle optional dollar signs, commas, and decimals. My goal is to match formats like `$1,234.56`, `1,234`, and `1234.56` while ensuring that it doesn't match invalid formats like `$12,34.56` or `$1,234.567`. I've created the following regex pattern: ```csharp string pattern = "^\$?(\d{1,3}(,\d{3})*)(\.\d{2})?$"; ``` However, I'm working with issues where it matches invalid strings, especially when I try to test strings like `$12,34.56`, which should not be matched. I've also attempted to break down the regex to make it clearer, but I'm still not getting the expected results. When I test it against the following strings: ```csharp string[] testStrings = { "$1,234.56", "$12,34.56", "$1234", "1234.56" }; ``` Using the regex with `Regex.IsMatch` method seems to give me a match for all entries, which is not what I intended. I would really appreciate any insights on how I can improve the regex to account for these edge cases and ensure that only valid currency formats are matched. I'm currently using .NET 5.0 and the Regex class from the System.Text.RegularExpressions namespace. Thanks for your help! This is part of a larger API I'm building. My development environment is Ubuntu. Hoping someone can shed some light on this. Any pointers in the right direction?