Java Intro

Question 1

What is Java?

Answer 1

A high-level, object-oriented programming language designed for minimal implementation dependencies.

Question 2

What is a key feature of Java that allows it to run on any device?

Answer 2

Platform-Independent: Runs on any device with Java Virtual Machine (JVM).

Question 3

What does object-oriented mean in the context of Java?

Answer 3

Uses classes and objects to model real-world entities.

Question 4

What is the basic structure of a Java program?

Answer 4

Arrangement of components including class declaration, main method, and statements.

Question 5

What is the purpose of ‘public class Main’ in a Java program?

Answer 5

Declares the class. Every program must have at least one class.

Question 6

What is the entry point of a Java program?

Answer 6

public static void main(String[] args)

Question 7

What does System.out.println() do in Java?

Answer 7

Prints text to the console.

Question 8

What is a variable in Java?

Answer 8

Stores changeable data during execution.

Question 9

What are primitive data types in Java?

Answer 9

Types that define the kind of data, such as:
* int
* double
* char
* boolean

Question 10

What is an example of a reference data type in Java?

Answer 10

String: Sequence of characters (e.g., ‘Hello, World!’)

Question 11

What is the difference between declaration and initialization of variables?

Answer 11

Declaration specifies the type and name; initialization assigns a value.

Question 12

Fill in the blank: To declare an integer variable in Java, use ______.

Answer 12

int x;

Question 13

What are operators in Java?

Answer 13

Symbols or keywords used to perform operations on variables/values.

Question 14

List the types of operators in Java.

Answer 14

• Arithmetic Operators
• Comparison Operators
• Logical Operators

Question 15

What is the purpose of comments in Java?

Answer 15

Non-executable lines for explaining code.

Question 16

What are the two types of comments in Java?

Answer 16

• Single-line: // Comment
• Multi-line: /* Comment */

Question 17

What is code formatting best practice in Java?

Answer 17

Structuring code for readability and consistency.

Question 18

What is recommended for variable names in Java?

Answer 18

Camel Case (e.g., myVariable)

Question 19

True or False: Java syntax is strict but logical.

Answer 19

True

Question 20

What is the role of variables, data types, and operators in Java?

Answer 20

Essential for data manipulation.

Question 21

How does code formatting and commenting affect Java code?

Answer 21

Improves readability and maintenance.

Question 22

What is the output of the following code: int a = 10; int b = 20; System.out.println(a + b);?

Answer 22

30

Question 23

What does the % operator do in Java?

Answer 23

Returns the remainder of division.

Question 24

Fill in the blank: A non-primitive data type in Java is ______.

Answer 24

String