Java

20220531

Fist notes on java programming.

public class HelloWorld {
	public static void main(String args[] ) {
		String text = "hello world";
		System.out.println( text );
	}
}

If a class implements an interface all methods in that interface must be defined in the class

Variables

int var1 = 0

Variables must be declared and initialized

private int var1;

Private variables in classes can only be accessed from within the class (same for methods).

Methods

• Every program must have a main method, that is executed when the program starts
• A 'void' method is a method with no return value, else the return value type must be specified
• Private methods in classes can only be accessed from within the class (same for variables).