27.01.26.md (509B)
1 # 27/01/26 2 3 # classes 4 5 - a class is a blueprint for a specific object 6 - generally objects start with uppercase letters 7 8 # class diagrams 9 10 - '-' minus means private 11 - '+' plus means public 12 13 # java 14 15 - the name of the 'main' class must be the name of the file 16 17 ``` 18 public class helloworld { 19 public static void main(String args[]) { 20 System.out.println("hello world!"); 21 } 22 } 23 ``` 24 25 - the java build system is `javac` -> `java` -> it runs 26 - you can use the `new` keyword to make an instance of a class