How can I test if a string is made up from different characters only?

Question

I have a 5 character long string from Console.Readline() and I want to test if all 5 characters are different.

Answer 1

You can use Distinct method which will give you the distinct characters then just compare the count with the input length, if they are equal that means all chars are different.

string input = Console.ReadLine();

bool isDifferent = input.Distinct().Count() == input.Length;

Note you need using System.Linq; to use Distinct method.