Grade 12 Java Programming Quiz

What are the primitive data types in Java?

• true, false, null, undefined

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

• string, array, object, null

• void, class, interface, package

Explain the difference between int and double data types in Java.

• The int data type is used to store decimal values, while the double data type is used to store whole numbers.

• The int data type is used to store integer values, while the double data type is used to store floating-point numbers with decimal values.

• The int data type is used to store floating-point numbers, while the double data type is used to store integer values.

• The int data type is used to store both integer and floating-point numbers, while the double data type is used to store only integer values.

What is the purpose of if-else statements in Java?

• To define new variables

• To print a message to the console

• To create loops in the code

• To make decisions based on certain conditions

How do you use a switch statement in Java?

• By using the for loop with conditional statements

• By using the try-catch block

• By using the if-else statement instead

• By using the switch keyword followed by the variable or expression in parentheses, and then using case and break statements to define different cases and their corresponding actions.

What is inheritance in Java?

• Inheritance in Java is used to create new classes from existing classes.

• Inheritance in Java is a way to override methods in a class.

• Inheritance in Java is not supported by the language.

• Inheritance in Java allows a class to inherit properties and behaviors from another class.

Explain the concept of polymorphism in Java.

• Polymorphism in Java allows methods to be inherited from a superclass to provide different implementations.

• Polymorphism in Java allows methods to be overloaded in a subclass to provide different implementations.

• Polymorphism in Java allows methods to be encapsulated in a subclass to provide different implementations.

• Polymorphism in Java allows methods to be overridden in a subclass to provide different implementations.

What is an exception in Java?

• A keyword used to define a class in Java

• A method for handling errors in Java

• A type of variable in Java

• An event that disrupts the normal flow of the program's instructions.

How do you handle exceptions in Java?

• Use try-catch blocks

• Ignore the exceptions

• Use if-else statements

• Throw the exceptions

What is the purpose of file handling in Java?

• To read from and write to files, as well as to perform various file operations such as creating, deleting, and modifying files.

• To send emails and messages

• To calculate mathematical operations

• To play music and videos

Explain the difference between FileReader and FileWriter in Java.

• FileReader is a subclass of FileWriter, FileWriter is a subclass of FileReader

• FileReader is for reading, FileWriter is for writing

• FileReader is used for both reading and writing, FileWriter is used for both reading and writing

• FileReader is for writing, FileWriter is for reading