如何检查字符串包含字母或数字 - 正则表达式c＃

Question

How to check Whether string contains Alphabets or Digits using Regular Expression. In a single regular expression How can i achieve this in c#.Currently i am finding alphabets like this

 Regex.Matches(folderPath, @"[a-zA-Z]").Count

Answer 1

Whether string contains Alphabets or Digits

For this case:

Regex.Matches(folderPath, @"[a-zA-Z0-9]").Count

should work.

Answer 2

In C#, you do not need regex to check if there are digits or alphabetic characters. Use LINQ with Char.IsLetterOrDigit() :

var hasAlphanum = "!?A1".Any(p => Char.IsLetterOrDigit(p)); // => true
var hasAlphanum1 = "!?1".Any(p => Char.IsLetterOrDigit(p)); // => true
var hasAlphanum2 = "!?".Any(p => Char.IsLetterOrDigit(p));  // => false

The .Any(p => Char.IsLetterOrDigit(p)) part is checking if any character inside the string conforms to the condition inside the brackets.

Answer 3

Do this:

string folderPath = "abc123";
Regex.IsMatch(folderPath, @"[a-zA-Z0-9]") // returns true

https://dotnetfiddle.net/faeZND