Introduction to Java

Question 1

What is Java?

Answer 1

It is a programming language created in 1995 that is owned by Oracle.

Question 2

When and where did the development of Java begin?

Answer 2

It began in the early 1990s at Sun Microsystems, led by James Gosling.

Question 3

What was the original name of the Java project?

Answer 3

It was called “Oak”.

Question 4

When was the name “Java” officially chosen, and what inspired it?

Answer 4

1994, inspired by a coffee blend flavor.

Question 5

When was the Java programming language formally announced?

Answer 5

at SunWorld ‘95.

Question 6

When was Java 1.0 released, and what was its slogan?

Answer 6

1995, “Write Once, Run Anywhere” (WORA)

Question 7

What new features were introduced with Java 1.1 in 1996?

Answer 7

Inner classes and the Abstract Window Toolkit (AWT)

Question 8

What major changes were introduced in Java 2 Platform (Java 1.2) in 1997?

Answer 8

1. Swing GUI toolkit
2. Collections Framework
3. Java Naming and Directory Interface

Question 9

What were the key updates in Java 1.3, released in 2000?

Answer 9

1. Performance Improvement
2. HotSpot JVM

Question 10

What features were introduced with Java 1.4 (J2SE 1.4) in 2002?

Answer 10

1. ‘assert’
2. Regular Expressions
3. Java Web Start

Question 11

What major features were introduced in Java 5, codenamed “Tiger,” in 2004?

Answer 11

1. Generics
2. Metadata Annotations
3. Enumerated Types
4. Enhanced For Loop

Question 12

What were the significant updates in Java 6, also known as “Mustang,” released in 2006?

Answer 12

1. Scripting Support via JC API

Question 13

What were the key features introduced in Java 7, codenamed “Dolphin,” in 2011?

Answer 13

1. Try-with-resources Statement
2. Diamond Operator
3. Fork/Join Framework

Question 14

What groundbreaking features were introduced in Java 8, codenamed “Lambdas,” in 2014?

Answer 14

1. Lambda Expressions
2. Stream API
3. java.time package

Question 15

What were the significant updates in Java 9, released in 2017?

Answer 15

1. Module System (Project Jigsaw)
2. HTTP/2 Client

Question 15

What were the key updates in Java 10 and Java 11, released in 2018?

Answer 15

1. 10 - Local-variable Type Interference (‘var’)
2. 11 - Long-term Support (LTS)

Question 16

What notable features were introduced in Java 12 and Java 13, released in 2019?

Answer 16

Java 12 and 13 introduced incremental features.

Question 17

What was introduced in Java 14, known as “Project Loom,” in 2020?

Answer 17

1. Fibers (lightweight, user-mode threads)

Question 18

What key features were added in Java 15, Java 16, and Java 17, released in 2021?

Answer 18

1. Records
2. Pattern Matching

Question 19

How can you check if Java is installed on a Windows PC?

Answer 19

Type ‘java -version’ in CMD.

Question 20

Where must every line of code that runs in Java be located?

Answer 20

Every line of code that runs in Java must be inside a class.

Question 21

What naming convention should you follow for a class in Java?

Answer 21

A class name in Java should always start with an uppercase letter.

Question 22

Is Java case-sensitive?

Answer 22

Yes.

“MyClass” and “myclass” have different meanings.

Question 23

What must be true about the filename of a Java file?

Answer 23

It must match the class name and should be saved with the “.java” extension.

Question 24

What is the purpose of the main() method in a Java program?

Answer 24

The main() method is required in every Java program, and any code inside it will be executed.

Question 25

What must match in every Java program, and what must every program contain?

Answer 25

The class name must match the filename, and every program must contain the main() method.

Question 26

What do the curly braces {} signify in a Java program?

Answer 26

The curly braces {} mark the beginning and end of a block of code.

Question 27

What are the purposes of comments in Java?

Answer 27

Comments in Java are used to explain code, make it more readable, and prevent execution when testing alternative code.

Question 28

How do you write a single-line comment in Java?

Answer 28

Single-line comments start with two forward slashes //.

Question 29

How do you write a multi-line comment in Java?

Answer 29

Multi-line comments start with /* and end with /. Any text between / and */ will be ignored by Java.

Question 30

How should text be handled in Java code?

Answer 30

Text must be wrapped inside double quotation marks “” in Java.

Question 31

What happens if you forget to use double quotes around text in Java?

Answer 31

If you forget the double quotes, an error will occur.

Question 32

How do you handle numbers in Java compared to text?

Answer 32

Unlike text, numbers are not put inside double quotes in Java.