C# indexer

In C#, an indexer is a special type of property that allows an object to be indexed just like an array. Indexers allow instances of a class or struct to be indexed like arrays. By using indexers, instances of a class can be accessed in the same way as an array. An indexer allows an instance of a class or struct to be indexed as an array.

An indexer is defined using the "this" keyword followed by square brackets that specify the type of the parameter. The syntax for defining an indexer is as follows:

public returnType this[type index] {  
    get {  
        // return the value  
    }  
    set {  
        // set the value  
    }  
}

Here, "returnType" is the data type of the value that the indexer returns, "type" is the data type of the index parameter, and "index" is the name of the index parameter.

Indexers can be used to access elements of an object in a manner similar to an array. For example, consider a class that represents a list of integers:

class IntList {
    private int[] list = new int[10];
    public int this[int index] {
        get {
            return list[index];
        }
        set {
            list[index] = value;
        }
    }
}

Here, the IntList class defines an indexer that allows the elements of the internal array to be accessed using square bracket notation. For example, myList[0] would return the first element of the internal array.

Indexers can also be overloaded, allowing multiple indexers with different parameter types or numbers of parameters to be defined within the same class.