What is covariance and contravariance in C#?

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Ponu Maurya · Answer

Answer:
Covariance and contravariance allow you to use a more derived or more base type than originally specified.
Covariance (out): Enables method to return a more derived type.Contravariance (in): Allows passing a less derived type as an argument.
IEnumerableandlt;stringandgt; strings = new Listandlt;stringandgt;(); // covariance
Actionandlt;objectandgt; act = (o) =andgt; Console.WriteLine(o); 
Actionandlt;stringandgt; strAct = act; // contravariance (invalid in this case) 
Applies to generic interfaces and delegates.

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What is covariance and contravariance in C#?

Ponu Maurya

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