Snippet

Null-Safe Input Validation

Checking for null or whitespace prevents security vulnerabilities and crashes caused by unexpected empty user input.

snippet.cs

csharp

using System;
 
public class Program {
    public static void RegisterUser(string username) {
        if (string.IsNullOrWhiteSpace(username)) {
            throw new ArgumentException("Username cannot be empty or whitespace.");
        }
        Console.WriteLine($"User {username} registered.");
    }
 
    public static void Main() {
        RegisterUser("Alex");
    }
}

Breakdown

string.IsNullOrWhiteSpace(username)

Returns true if the string is null, empty, or consists only of white-space characters.

throw new ArgumentException(...)

Halts execution and notifies the caller that the input was invalid.

Previous snippet Next snippet

More Beginner C# exercises →

Null-Safe Input Validation

Related