Java Fundamentals

What are the different data types in Java?

• integer, decimal, character, true/false, and text

• float, long, byte, short, and array

• number, string, boolean, character, and array

• int, double, char, boolean, and String

Explain the difference between int and Integer in Java.

• int is used for whole numbers, while Integer is used for decimal numbers

• int is immutable, while Integer is mutable

• Integer is a class, while int is a primitive data type.

• int can be used for mathematical operations, while Integer cannot

What is the purpose of the 'final' keyword in Java?

• To allow the user to change the value of a variable

• To make a method optional

• To automatically initialize a variable

• To restrict the user from changing the value of a variable or to make a method unchangeable.

How do you declare a variable in Java?

• By using the syntax: int variableName = value;

• By using the syntax: variableName = value;

• By using the syntax: var variableName = value;

• By using the syntax: type variableName;

What are the different types of control statements in Java?

• if-else, switch, for, while, and do-while, and repeat

• if-else, switch, for, while, and do-while

• if-else, switch, for, while, and do-while, and when

• if-else, switch, for, while, and do-while, and until

Explain the use of 'if-else' statement in Java with an example.

• The use of 'if-else' statement in Java is to loop through an array

• The use of 'if-else' statement in Java is to make decisions based on a condition.

• The use of 'if-else' statement in Java is to print 'Hello World'

• The use of 'if-else' statement in Java is to define a class

What is inheritance in Java?

• Inheritance in Java is a process of creating a new class by extending an existing class.

• Inheritance in Java is a feature that allows a class to inherit properties from multiple classes.

• Inheritance in Java allows one class to inherit the properties and behaviors of another class.

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

Explain the concept of polymorphism in Java.

• Polymorphism in Java allows methods to be written that can work with objects of different classes and perform different actions based on the object being used.

• Polymorphism in Java is the ability to define multiple methods with the same name in a class.

• Polymorphism in Java is the process of creating multiple methods with the same name but different implementations.

• Polymorphism in Java refers to the ability of a variable, a method, or an object to take on multiple forms.

What is an exception in Java?

• An exception in Java is an event that disrupts the normal flow of the program's instructions.

• An exception in Java is a feature that enhances program performance

• An exception in Java is a type of variable

• An exception in Java is a common occurrence in programming

How do you handle exceptions in Java?

• By using try-catch blocks

• By ignoring the exceptions

• By using if-else statements

• By using switch-case statements