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 ConsoleApplication712 {13     class Program14     {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                 else29                 {30                     Console.WriteLine(contents[i] + "不符合正则表达式");31 32                 }33             }34 35             Console.ReadKey();36         }37     }38 }