When should you use C indexers

Question

I'd like to utilise indexers more often, but I'm not sure when it's appropriate to do so. All of the examples I've found online use classes like MyClass and IndexerClass.

Is there a need for indexers in a school system where there are Students and Teachers, and each Teacher has a list of Students that they are responsible for? For the sake of simplicity, each Student can only have one Teacher.

Answer 1

First, let's talk about indexer. Class (or struct) instances can be indexed like array elements thanks to a highly specialised attribute called the indexer (properties can be static but indexers cannot).

Now, why should you use indexer

1. The class becomes the data structure instead of the new data structure
2. Syntax is easy

With that said, when shoule you use indexer? If your class requires list or arrays of its instances. Here's a code to show this

public class Person{
    public string Name{get; set;}
    
    private Person[] _backingStore;
    public Person this[int index]
    {
        get{
            return _backingStore[index];
        }
        set{
            _backingStore[index] = value;
        }
    }
}

Person p = new Person();
p[0] = new Person(){Name = "Bostov"};
p[1] = new Person(){Name = "Mindy Tow"};