The document provides information about an intro to Java course including enrollment details, meetup session information, and recaps of course content. Enrollment details include the course website, contact email, and where to find FAQs. Meetup sessions will be virtual with instructions provided on muting/unmuting lines and encouraging discussions. Recaps cover what coding is, the components inside a computer, an introduction to Java including how it can run on any machine, and a simple "Hello World" Java program.
2. Enrollment
Course Website – http://introtojava.usefedora.com/
• Course – Video study materials and assignments
• Contact – hello@introtojava.com
• FAQs on website – if not covered, please ask
3. Meetup sessions
Virtual Meetup
• Enter your name. Click on people icon and your name is the first in the list
• All lines will be muted at the beginning of the session
• Use *6 to un-mute your line if you have a question or comment
• Send your feedback to hello@introtojava.com
Meetup sessions
• Lots of discussion, please ask questions
• Quick recap of study material videos
• Discuss assignments, problems faced
• Encourage discussions with fellow learners – teamwork
• Same goal for everyone – Get started with coding!
4. Recap: What is Coding?
1. Take the two number numbers to be
multiplied, call them A and B.
2. Start your calculation with 0.
3. Add the first number - A, to your
calculation, and keep track of how many
times you have added A.
4. If you have added less than B times, then
do step 3 again.
5. Now you have your answer ... ☺
Lets check if it works !!
Calculate 3 times 4
1) Take A is 3, and B is 4.
2) Start Calculation with 0.
3) Calculation is 3, and added 1 time.
3) Calculation is 6, and added 2 times.
3) Calculation is 9, and added 3 times.
3) Calculation is 12, and added 4 times.
4) Added 4 times, continue.
5) We have our answer - 12
5. Recap: What is Coding?
Let’s create an English-like language that,
• ... only allows certain words
• ... must follow strict rules (called “syntax”)
and we will call it a Programming Language!
Everyone invented their own ☺
- Java, C, COBOL, Ruby, Python etc.
Coding - writing instructions in a Programming Language
• e.g. “I like to code in Java”, or “Coding in Java is so much easier than C”.
James Gosling:
Inventor of Java
6. Recap Video: Inside a Computer
INPUT DEVICES
(builtin)
OUTPUT DEVICES
(builtin)
MEMORY
(RAM)
PROCESSOR
(CPU)
CONNECTORS
INPUT
(external)
OUTPUT
(external)
Human Computer
Keyboard, Hard
drive, Webcam
Display, Hard,
drive, Speakers
USB, Video
Mic, Thumb drive,
Scanner
Printer, Thumb
drive, Projector
Human Computer Interface –
point of communication between
people and computer using devices,
voice, touch etc.
7. Recap Video: Inside a Computer
How to “program” a computer
1. Write the algorithm for processing the input data
2. Write the instructions in a Programming Language, e.g. Java
3. Convert from Programming Language to Machine Language code
4. Load the Machine Language code into MEMORY
5. CPU executes all the steps in the code
6. Check that everything works as expected
We have programs that will Compile, Load and Run for us,
but we must Design, Code and Test our programs ...
DESIGN
CODE
COMPILE
RUN
TEST
8. Recap Video: Introducing Java
• Imagine an “ideal” computer – call it Java
Virtual Machine with its own JVM machine
language (called bytecode)
• Compile Java code to bytecode (instead of
CPU Machine Language)
• Before Run, convert bytecode into the
Machine Language of the specific CPU
(JVM software)
Java is Compile once, Run anywhere
(also called as portability)
9. Recap Video: Hello World
public class HelloWorld {
public static void main(String[] args) {
System.out.println("Hello World");
}
}
Common rules of Java language
• Language reserves 50 key words
• e.g. class, public, try, String
• Each instruction ends with “;”
• Each block starts with “{”, ends with “}”
• All programs start with “main”
10. Empty Program
public class HelloWorld {
public static void main(String[] args) {
}
}
Common rules of Java language
• Language reserves 50 key words
• e.g. class, public, try, String
• Each instruction ends with “;”
• Each block starts with “{”, ends with “}”
• All programs start with “main”
