In object-oriented programming, a covariant return type
of a method is one that can be replaced by a "narrower" type when the
method is overridden in a subclass.
C# does not support return type covariance. Covariant
return types have been (partially) allowed in the Java language since the
release of JDK5.0.
However if the return type is void or
primitive then the data type of parent class method and overriding method
should be same.
class Parent
{
Parent getCovariant() {
return this;
}
void
getMessage() {
System.out.println("Covariant return type!!");
}
}
class
TestCovariant extends Parent {
TestCovariant getCovariant()
{
return this;
}
public static void main(String
args[]) {
new TestCovariant().getCovariant().getMessage();
}
}
Output:
Covariant return type!!
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