Question

How to check if string contain lowercase letters, uppercase letters, or digits in C#

Answer 1

using System;
using System.Text.RegularExpressions;

namespace ConsoleApplication_C_Sharp
{
    static class Program
    {
        static void Main()
        {
            string s1 = "CSHARPNET13Java89Python";
            Console.WriteLine(Regex.IsMatch(s1, "^[a-zA-Z0-9]*$"));

            string s2 = "!**!***!";
            Console.WriteLine(Regex.IsMatch(s2, "^[a-zA-Z0-9]*$"));

            string s3 = "CSHARP 13 Java 89 Python";
            Console.WriteLine(Regex.IsMatch(s3, "^[a-zA-Z0-9]*$"));

            string s4 = "CSHARPJavaPython";
            Console.WriteLine(Regex.IsMatch(s4, "^[a-zA-Z0-9]*$"));

            string s5 = "csharpjavapython";
            Console.WriteLine(Regex.IsMatch(s5, "^[a-zA-Z0-9]*$"));

            string s6 = "CSHARPJAVAPYTHON";
            Console.WriteLine(Regex.IsMatch(s6, "^[a-zA-Z0-9]*$"));

            string s7 = "1230998";
            Console.WriteLine(Regex.IsMatch(s7, "^[a-zA-Z0-9]*$"));
        }
    }
}


/*
run:
  
True
False
False
True
True
True
True
   
*/

 

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