Given the following classes:class Shape { /* ... */ }class Circle extends Shape { /* ... */ }class Rectangle extends Shape { /* ... */ }class Node<T> { /* ... */ }Will the following code compile?Node<Circle> nc = new Node<>();Node<Shape> ns = nc;Select one:a. Yesb. No
Question
Given the following classes:class Shape { /* ... / }class Circle extends Shape { / ... / }class Rectangle extends Shape { / ... / }class Node<T> { / ... */ }Will the following code compile?Node<Circle> nc = new Node<>();Node<Shape> ns = nc;Select one:a. Yesb. No
Solution
b. No
The code will not compile. In Java, generics are not covariant, meaning that even though Circle is a subclass of Shape, Node<Circle> is not a subclass of Node<Shape>. Therefore, you cannot assign a Node<Circle> to a variable of type Node<Shape>.
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