Covariant Return Type

When Variance of return types if covariant.

Two examples where this can work -

• Suppose there are two classes A and B. A has a function with return type A and B has the function with the same name and arguments but with return type B. The function in B can override the one in A in this situation.
• Suppose there are four classes A, B, C and D. A is inherited by C and B is inherited by D. Now C has a function with return type A and D has a method with same name and arguments with return type B. Method overriding works here.

Basically, the parent return type is being replaced by child return type in the overriding method.

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Backlinks

• Overriding (cs)
• Overriding by Return Types (cs)