Java Fundamentals Assessment

What are the primitive data types in Java?

• byte, short, int, long, float, double, char, boolean

• text, number, flag

• integer, decimal, character

• string, list, map

Explain the difference between 'if' and 'switch' statements.

• 'if' statements can only handle two conditions, while 'switch' can handle more than two.

• The 'if' statement is for conditional branching, while 'switch' is for selecting among multiple cases based on a variable's value.

• 'if' statements evaluate expressions, while 'switch' evaluates boolean values.

• 'if' statements are used for loops, whereas 'switch' is used for functions.

What is encapsulation in Object-Oriented Programming?

• Encapsulation is the bundling of data and methods that operate on that data within a single unit, restricting access to some components.

• Encapsulation is the method of exposing all data and methods to the public.

• Encapsulation refers to the inheritance of properties from a parent class.

• Encapsulation is the process of creating multiple instances of a class.

How do you handle exceptions in Java?

• Ignore exceptions and continue execution.

• Use try-catch blocks to handle exceptions in Java.

• Throw exceptions without handling them.

• Use if-else statements to handle exceptions in Java.

What is the purpose of the ArrayList class in Java?

• The purpose of the ArrayList class in Java is to provide a dynamic array that can grow and shrink in size, allowing for flexible storage and manipulation of elements.

• To create a multi-dimensional array in Java.

• To implement a stack data structure in Java.

• To provide a fixed-size array for storing elements.

Describe the try-catch block in exception handling.

• The try-catch block is a way to declare variables in programming.

• The try-catch block is a mechanism for handling exceptions in programming, allowing for graceful error management.

• The try-catch block is used to define functions in programming.

• The try-catch block is a method for optimizing code performance.

What is the difference between a HashMap and a TreeMap?

• HashMap is unordered and faster (O(1)), while TreeMap is ordered and slower (O(log n)).

• Both HashMap and TreeMap are unordered and have the same performance (O(n)).

• HashMap is ordered and faster (O(1)), while TreeMap is unordered and slower (O(log n)).

• TreeMap is faster (O(1)) and HashMap is slower (O(log n)).

How do you read a file using File I/O in Java?

• Use BufferedReader with FileReader to read a file line by line.

• Use Scanner to read a file character by character.

• Read the entire file into a byte array at once.

• Utilize PrintWriter to write to a file instead of reading.

What is polymorphism in Java?

• Polymorphism is a feature that allows Java to run on any operating system.

• Polymorphism refers to the process of compiling Java code into bytecode.

• Polymorphism is the ability of a single function or method to operate in different ways based on the object it is acting upon.

• Polymorphism is the ability to create multiple classes in Java.

Explain the concept of inheritance in Java.

• Inheritance in Java allows a subclass to inherit properties and methods from a superclass, promoting code reusability and establishing a class hierarchy.

• Inheritance in Java restricts access to methods and properties of a class.

• Inheritance in Java allows a class to create multiple instances of itself.

• Inheritance in Java is a way to define interfaces without implementation.