Java Knowledge Check

What is the main entry point of a Java application?

• static void main(String[] args)

• void main(String[] args)

• public static void main(String[] args)

• public void main(String[] args)

Which of the following is a primitive data type in Java?

• int

• char

• float

• boolean

What keyword is used to create a class in Java?

• define

• class

• function

• create

In Java, what is the purpose of the 'this' keyword?

• The 'this' keyword is used to access class-level variables.

• The 'this' keyword is used to define static methods.

• The 'this' keyword is used to create new objects.

• The 'this' keyword is used to refer to the current object instance.

What is the output of the following code: System.out.println(5 + 3 + "8");?

• 83

• 58

• 88

• 53

What is inheritance in Object-Oriented Programming?

• Inheritance is a way to create multiple instances of a class.

• Inheritance allows a class to be deleted from memory.

• Inheritance is a method to encapsulate data within a class.

• Inheritance is a mechanism in OOP that allows a subclass to inherit properties and methods from a superclass.

Which of the following is NOT a feature of Object-Oriented Programming?

• Procedural programming

• Declarative programming

• Scripting languages

• Functional programming

What is polymorphism in Java?

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

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

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

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

How do you define a method in Java?

• A method in Java is defined using the syntax: accessModifier returnType methodName(parameterType parameterName) { // method body }.

• A method in Java is declared as: accessModifier methodName(parameterType) returnType { // method body }.

• In Java, a method is created using the syntax: returnType methodName() { // method body }.

• A method in Java is defined with the syntax: methodName(parameterType parameterName) { // method body }.

What is the difference between an interface and an abstract class in Java?

• An interface can have instance variables and allows single inheritance.

• An abstract class cannot have methods and allows multiple inheritance.

• An interface can only be implemented by one class and cannot have default methods.

• An interface cannot have instance variables and allows multiple inheritance, while an abstract class can have instance variables and allows single inheritance.