The document discusses the basics of Java including: - How Java code is compiled from source code by a compiler into bytecode that runs on a virtual machine. - The structure of Java code including classes and methods. - Using the Eclipse integrated development environment to write and run Java code. - Examples of Java statements, loops, branching, and boolean tests.

1. Head First Java Chapter 1
Tom Henricksen

2. The Way Java Works
● Source
● Compiler
● Output(code)
● Virtual Machine

3. Code Structure in Java
● Source
● Class
● Method

4. Eclipse

5. Eclipse

6. Eclipse

7. Eclipse

8. Eclipse

9. Eclipse

10. HelloWorld
public class HelloWorld {
public static void main (String[] args) {
System.out.println(“Hello World”);
}
}

11. Run your application

12. Run your application

13. Statements
//declaration
String name;
//assignment
name = “Tom”;
//method call
double d = Math.Random();

14. Loops
while (score > 10) {
score = score + 1;
}
For (int v = 0; v < 5; v++) {
System.out.println(v);
}

15. Branching
if (x = 10) {
System.out.println(“x is ten”);
} else {
System.out.println(“x is NOT ten”);
}

16. Boolean tests
< (less than)
> (greater than)
== (equality)
while (x < 10) {
x = x + 1;
}

17. NameLoop.java
public class NameLoop {
public static void main (String[] args) {
int x = 1;
while (x < 10) {
System.out.println(“My name is Tom!”)
}
}

18. Java Basics
● Statements end with a semicolon;
● Code blocks are defined by curly braces {}
● Declare an int variable with a name and a type: int x;
● The assignment operator is one equals sign =
● The equals operator uses two equals signs ==

19. Java Basics
● A while loop runs everything within its block as long as
conditional test is true
● If the conditional is false, the while loop code block won’t
run, and execution will move down
● Put your boolean test within parentheses
while (x==4) {}

20. Exercise