Java Programming - Java is a general-purpose computer-programming language that is concurrent, class-based, object-oriented, and specifically designed to have as few implementation dependencies as possible.

1. with eclipse IDE – Theory Part 1
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MARK JOHN P. LADO
Bachelor of Science in Information System
Instructor – Colegio de San Antonio de Padua - Guinsay, Danao City, Cebu Philippines
PROGRAMMING

2. What Is Java?
• Java is built on C++ for a simple-to-use language
• Java is a computer programming language. It enables
programmers to write computer instructions using
English-based commands instead of having to write in
numeric codes. It’s known as a high-level language
because it can be read and written easily by humans.

3. What Is Java?
• Like English, Java has a set of rules that determine how
the instructions are written. These rules are known as its
syntax. Once a program has been written, the high-level
instructions are translated into numeric codes that
computers can understand and execute.

4. Who Created Java?
• In the early 90s, Java, which originally went by the name
Oak and then Green, was created by a team led by James
Gosling for Sun Microsystems, a company now owned
by Oracle.
• Java was originally designed for use on digital mobile
devices, such as cellphones. However, when Java 1.0 was
released to the public in 1996, its main focus had shifted to
use on the internet, providing interactivity with users by
giving developers a way to produce animated web pages.

5. Who Created Java?
• However, there have been many updates since version
1.0, like J2SE 1.3 in 2000, J2SE 5.0 in 2004, Java SE 8 in
2014, and Java SE 10 in 2018.
• Over the years, Java has evolved as a successful
language for use both on and off the internet.

6. Why Choose Java?
• Java was designed with a few key principles in mind:
• Ease of Use: The fundamentals of Java came from
a programming language called C++. Although C++ is a
powerful language, it is complex in its syntax and
inadequate for some of Java's requirements. Java built
on and improved the ideas of C++ to provide a
programming language that was powerful and simple to
use.

7. Why Choose Java?
• Java was designed with a few key principles in mind:
• Reliability: Java needed to reduce the likelihood of fatal
errors from programmer mistakes. With this in
mind, object-oriented programming was introduced.
When data and its manipulation were packaged
together in one place, Java was robust.

8. Why Choose Java?
• Java was designed with a few key principles in mind:
• Security: Because Java was originally targeting mobile
devices that would be exchanging data over networks, it
was built to include a high level of security. Java is
probably the most secure programming language to
date.

9. Why Choose Java?
• Java was designed with a few key principles in mind:
• Platform Independence: Programs need to work
regardless of the machines they're being executed on.
Java was written to be a portable and cross-platform
language that doesn't care about the operating system,
hardware, or devices that it's running on.

10. Using Java Comments
• All Programming Languages Support Comments Which
are Ignored by the Compiler
• Java comments are notes in a Java code file that are
ignored by the compiler and runtime engine. They are
used to annotate the code in order to clarify its design
and purpose. You can add an unlimited number of
comments to a Java file, but there are some "best
practices" to follow when using comments.

11. Using Java Comments
• All Programming Languages Support Comments Which
are Ignored by the Compiler
• Generally, code comments are "implementation"
comments that explain the source code, such as
descriptions of classes, interfaces, methods, and fields.
These are usually a couple of lines written above or
beside Java code to clarify what it does.

12. Using Java Comments
• All Programming Languages Support Comments Which
are Ignored by the Compiler
• Another type of Java comment is a Javadoc comment.
Javadoc comments differ slightly in syntax from
implementation comments and are used by the program
javadoc.exe to generate Java HTML documentation.

13. Question…
•Why Use Java Comments?

14. Why Use Java Comments?
• It's good practice to get into the habit of putting Java
comments into your source code to enhance its
readability and clarity for yourself and other
programmers. It isn't always instantly clear what a
section of Java code is performing. A few explanatory
lines can drastically reduce the amount of time it takes
to understand the code.

15. Question…
•Do They Affect How The
Program Runs?

16. Do They Affect How The Program Runs?
• Implementation comments in Java code are only there
for humans to read. Java compilers don't care about
them and when compiling the program, they just skip
over them. The size and efficiency of your compiled
program will not be affected by the number of
comments in your source code.

17. Implementation Comments
Implementation comments come in two different formats:
1. Line Comments: For a one line comment, type "//" and
follow the two forward slashes with your comment.
For example:
// this is a single line comment

18. Implementation Comments
• When the compiler comes across the two forward
slashes, it knows that everything to the right of them is
to be considered as a comment. This is useful when
debugging a piece of code.

19. Implementation Comments
Implementation comments come in two different formats:
2. Block Comments: To start a block comment, type "/*".
Everything between the forward slash and asterisk, even if
it's on a different line, is treated as a comment until the
characters "*/" end the comment.

20. Implementation Comments
For example:
/* this
* is
* a
* block
* comment
*/

21. Example Code with comment
/*This is my first program in java
* Another line here
*/​
public static void main(String[] args)
{
System.out.println ("Hello World!");​
}

22. 4 Tips for Using Comments
1. Don't over comment. Every line of your program does
not need to be explained. If your program flows logically
and nothing unexpected occurs, don't feel the need to add
a comment.

23. 4 Tips for Using Comments
2. Indent your comments. If the line of code you are
commenting is indented, make sure your comment
matches the indentation.

24. 4 Tips for Using Comments
3. Keep comments relevant. Some programmers are
excellent at modifying code, but for some reason forget to
update the comments. If a comment no longer applies,
then either modify or remove it.

25. 4 Tips for Using Comments
4. Don't nest block comments. The following will result in
a compiler error:

26. Java Is Case Sensitive
• Case Sensitivity in Programming Languages is Common
• Java is a case-sensitive language, which means that the
upper or lower case of letters in your Java programs
matter.

27. Java Is Case Sensitive
About Case Sensitivity
• Case sensitivity enforces capital or lower case in text.
For example, suppose you have created three variables
called "endLoop", "Endloop", and "EndLoop". Even
though these variables are composed of the exact same
letters in the same exact order, Java does not consider
them equal. It will treat them all differently.

28. Java Is Case Sensitive
About Case Sensitivity
• This behavior has its roots in the programming language
C and C++, on which Java was based, but not all
programming languages enforce case sensitivity. Those
that do not include Fortran, COBOL, Pascal and most
BASIC languages.

29. What are the types of Java?
Data types in Java are classified into two types:
• Primitive—which include Integer, Character, Boolean,
and Floating Point.
• Non-primitive—which include Classes, Interfaces, and
Arrays.