1. The eclipse IDE IDE = “Integrated Development Environment”
Contains all the utilities needed to write, build, test, and publish source code
Has deep integration with specific programming languages
Can detect errors before they occur
Helps maintain good documentation for your code, and provide easy-to-access references
To set up eclipse:
Start program
Designate ”workspace” folder – this will contain all your different projects

2. Your to-do list
Shows the source file you
are currently editing
Shows your project files
Code outline
Shows errors and text output

3. To start coding:
Right-click in the “Package Explorer” pane and select “New” > “Java Project”
Alternative, navigate from the “File” menu

4. Name your project “HelloWorld”
Click “Finish” button

5. Create a new source file
Right click or go to “File” menu
Navigate to “New” -> “Class”

6. Create a new source file
Right click or go to “File” menu
Navigate to “New” -> “Class”
Name your class “HelloWorld”
Leave other options as default
Click “Finish”

7. Create a new source file
Right click or go to “File” menu
Navigate to “New” -> “Class”
Name your class “HelloWorld”
Leave other options as default
Click “Finish”

8. public class HelloWorld { } Notes:
What you see now:
A file called “HelloWorld.java”
Contains text:
public class HelloWorld { }
Notes:
In Java, every file contains one “Class”
Denoted by the keyword “class”
The name of the file must match exactly one “public” class defined in the top-level of the file
You can define more public and private classes within that class though (more later)
The keyword “public” is special, and means that this class can be referenced from outside the file
The braces { and } together create a block of code
The class name must must proceed a code block (even an empty one, as above)

9. Edit “HelloWorld.java” to contain:
Be careful! (Almost) every single character matters
Case-sensitive!
/**
* The HelloWorld class prints “Hello, World!”
* to the console. */
public class HelloWorld {
public static void main( String[] args ) {
System.out.println(“Hello, World!”); }

10. Your first program!

11. Run you program!
Click the “Run” button at the top, or “Run As” -> “Java Application”

12. Program Output Check your console at the bottom
Text output, if any, appears here
Compile errors will appear here as well

13. Program Errors IMPORTANT RULES
Declarations and expressions must end in semicolons (;)
Capitalization matters
Braces, parentheses, brackets must be matched
Demo: try removing the semicolon from line 7 of your program
Run the program
What happens?

14. Compile Error!
When you try and run without the proper syntax (code structure) the compiler will halt with an error message
Tells you the line where the error was detected
HelloWorld.java:7
Eclipse is smart enough to detect this error before you compile, though
Standard text editors could not do this!