C#正则表达式基础 ^[0-9] 检测字符串的首个字符是否是数字

1 代码

 1 //^[0-9] 检测字符串的首个字符是否是数字
 2
 3 using System;
 4 using System.Collections.Generic;
 5 using System.Linq;
 6 using System.Net;
 7 using System.Text;
 8 using System.Text.RegularExpressions;
 9 using System.Threading.Tasks;
10
11 namespace ConsoleApplication7
12 {
13     class Program
14     {
15         static void Main(string[] args)
16         {
17
18             string regularExpression = @"^[0-9]";
19             Regex rg = new Regex(regularExpression);
20
21             string [] contents = { @"@@@", @"1%^&34", "a3bb33345", "a321b3" };
22             for (int i = 0; i < contents.Length; i++)
23             {
24                 if(rg.IsMatch(contents[i]))
25                 {
26                     Console.WriteLine(contents[i]+"符合正则表达式");
27                 }
28                 else
29                 {
30                     Console.WriteLine(contents[i] + "不符合正则表达式");
31
32                 }
33             }
34
35             Console.ReadKey();
36         }
37     }
38 }

2 效果