Introduction to Java Flashcards
What is Java?
It is a programming language created in 1995 that is owned by Oracle.
When and where did the development of Java begin?
It began in the early 1990s at Sun Microsystems, led by James Gosling.
What was the original name of the Java project?
It was called “Oak”.
When was the name “Java” officially chosen, and what inspired it?
1994, inspired by a coffee blend flavor.
When was the Java programming language formally announced?
at SunWorld ‘95.
When was Java 1.0 released, and what was its slogan?
1995, “Write Once, Run Anywhere” (WORA)
What new features were introduced with Java 1.1 in 1996?
Inner classes and the Abstract Window Toolkit (AWT)
What major changes were introduced in Java 2 Platform (Java 1.2) in 1997?
- Swing GUI toolkit
- Collections Framework
- Java Naming and Directory Interface
What were the key updates in Java 1.3, released in 2000?
- Performance Improvement
- HotSpot JVM
What features were introduced with Java 1.4 (J2SE 1.4) in 2002?
- ‘assert’
- Regular Expressions
- Java Web Start
What major features were introduced in Java 5, codenamed “Tiger,” in 2004?
- Generics
- Metadata Annotations
- Enumerated Types
- Enhanced For Loop
What were the significant updates in Java 6, also known as “Mustang,” released in 2006?
- Scripting Support via JC API
What were the key features introduced in Java 7, codenamed “Dolphin,” in 2011?
- Try-with-resources Statement
- Diamond Operator
- Fork/Join Framework
What groundbreaking features were introduced in Java 8, codenamed “Lambdas,” in 2014?
- Lambda Expressions
- Stream API
- java.time package
What were the significant updates in Java 9, released in 2017?
- Module System (Project Jigsaw)
- HTTP/2 Client
What were the key updates in Java 10 and Java 11, released in 2018?
- 10 - Local-variable Type Interference (‘var’)
- 11 - Long-term Support (LTS)
What notable features were introduced in Java 12 and Java 13, released in 2019?
Java 12 and 13 introduced incremental features.
What was introduced in Java 14, known as “Project Loom,” in 2020?
- Fibers (lightweight, user-mode threads)
What key features were added in Java 15, Java 16, and Java 17, released in 2021?
- Records
- Pattern Matching
How can you check if Java is installed on a Windows PC?
Type ‘java -version’ in CMD.
Where must every line of code that runs in Java be located?
Every line of code that runs in Java must be inside a class.
What naming convention should you follow for a class in Java?
A class name in Java should always start with an uppercase letter.
Is Java case-sensitive?
Yes.
“MyClass” and “myclass” have different meanings.
What must be true about the filename of a Java file?
It must match the class name and should be saved with the “.java” extension.
What is the purpose of the main() method in a Java program?
The main() method is required in every Java program, and any code inside it will be executed.
What must match in every Java program, and what must every program contain?
The class name must match the filename, and every program must contain the main() method.
What do the curly braces {} signify in a Java program?
The curly braces {} mark the beginning and end of a block of code.
What are the purposes of comments in Java?
Comments in Java are used to explain code, make it more readable, and prevent execution when testing alternative code.
How do you write a single-line comment in Java?
Single-line comments start with two forward slashes //.
How do you write a multi-line comment in Java?
Multi-line comments start with /* and end with /. Any text between / and */ will be ignored by Java.
How should text be handled in Java code?
Text must be wrapped inside double quotation marks “” in Java.
What happens if you forget to use double quotes around text in Java?
If you forget the double quotes, an error will occur.
How do you handle numbers in Java compared to text?
Unlike text, numbers are not put inside double quotes in Java.
