C#正则表达式基础 | 或 [0-9]|[a-z]|[A-Z] 验证一个字符是否是数字或者字母

 1 using System;
 2 using System.Collections.Generic;
 3 using System.Linq;
 4 using System.Net;
 5 using System.Text;
 6 using System.Text.RegularExpressions;
 7 using System.Threading.Tasks;
 8 
 9 namespace ConsoleApplication7
10 {
11     class Program
12     {
13         static void Main(string[] args)
14         {
15             //" [0-9]|[a-z]|[A-Z] "，正则表达式前后有空格的话，不会出现正确结果。不明觉厉
16             string regularExpression = "[0-9]|[a-z]|[A-Z]";
17             Regex rg = new Regex(regularExpression);
18 
19             string contents = "0123456789abcdefgABCDEFG";
20             for (int i = 0; i < contents.Length; i++)
21             {
22                 if(rg.IsMatch(contents[i].ToString()))
23                 {
24                     Console.WriteLine(contents[i]+"符合正则表达式");
25                 }
26                 else
27                 {
28                     Console.WriteLine(contents[i] + "不符合正则表达式");
29 
30                 }
31             }
32 
33             Console.ReadKey();
34         }
35     }
36 }