Complete Java SE 8 Developer Bootcamp - Polymorphism Revisited

The video tutorial explains the concept of arrays and polymorphism in programming. It introduces a class hierarchy involving Person, Employee, Manager, and Secretary, and demonstrates how polymorphism allows different objects to be stored in an array of a common type. The tutorial covers array operations, including subscripting and casting, and discusses the limitations of accessing subclass-specific methods. It also explains how to iterate through arrays using traditional for loops and for-each loops, highlighting the redundancy of explicitly calling the toString method when printing objects.

What does it mean for an array to be polymorphic?

• It can only hold primitive data types.

• It can change its size dynamically.

• It can hold objects of a specified type and its subtypes.

• It can only hold objects of a single type.

Which class in the hierarchy adds a salary attribute?

• Manager

• Employee

• Person

• Secretary

Why is encapsulation important in real-world coding?

• It simplifies the class hierarchy.

• It protects data by restricting access to class attributes.

• It allows direct access to class attributes.

• It makes code easier to read.

What is required to access a manager's department attribute from an employee array?

• Using a getter method.

• Direct access through the array index.

• Using a special array method.

• Casting the object to a Manager type.

How can you iterate over an array to print each employee's name?

• Using a do-while loop.

• Using a while loop.

• Using a traditional for loop or a for-each loop.

• Using a recursive function.

What is the advantage of using a for-each loop over a traditional for loop?

• It can iterate over multiple arrays simultaneously.

• It automatically sorts the array elements.

• It simplifies the syntax for iterating over collections.

• It allows for dynamic resizing of the array.

What happens when you pass an object to the print line method without calling toString?

• It automatically calls the object's toString method.

• It prints nothing.

• It prints the object's memory address.

• It throws an error.