Mastering Java: The Ultimate Quiz for 'Thinking in Java'

Why use the private keyword?

1. To restrict access to a member within its package

2. To allow subclasses to access a member

3. To prevent any class outside the defining class from accessing the member

4. To make a member accessible to everyone

The correct answer is: To prevent any class outside the defining class from accessing the member

The private keyword is used to designate a member as only accessible within the defining class. Options A and B are incorrect because they both allow some level of access to the member outside of the defining class. Option D is incorrect because it allows unrestricted access to the member, which can lead to potential security risks. It is important to use the private keyword to control access to sensitive data and ensure proper encapsulation within the class.