Objectives

1. Understand what a text editor is.
2. Understand the edit -> compile -> execute cycle
3. Enter a first Java Program

Notes

• To write programs we need one more tool, a text editor.
  • A text editor is a program that allows us to put text into a file.
• The Edit - Compile - Execute cycle
  • We will use the text editor to put Java code in a .java file.
  • We will then use the Java compiler to produce java byte-code
  • We will thin use the JRE to try to run or execute that code.
• For this I will use a simple program.
  • Hello World! is a very simple, program people often use to demonstrate the programming process.
  • In Java hello world is:

  • class HelloWorld {
        public static void main(String[] args) {
            System.out.println("Hello World!");
        }
    } 

  • We will create this program in a number of environments.
  • One side note, when we save the program, it must be called HelloWorld.java.
  • We will work on understanding this program in the next video.
• In jGRASP
  • jGRASP is a development environment
  • This is is what Dr. Kovalchick uses.
  • I will use it in the beginning.
  • It is fairly easy to use.
  • Do a demo.
• You don't need the fancy environment if you want to be more simple:
  • Notepad comes on most windows box.
  • Notepad++ is aimed at programming.
  • Do a demo.
• I use a program called VIM
• Dr. Menon uses the eclipse IDE.
• Visual Studio Code is very popular.
• You need to work out an environment in which you will work.
  • Any of the above will do.
  • I think jGRASP is probably the easiest for beginners.