Writing My First Java Program

Java Tutorials - Herong's Tutorial Notes

Dr. Herong Yang, Version 6.00

∟Writing My First Java Program

This section provides a tutorial example on how to write, compile, and execute the first Java program with JDK 1.5.0. Notes were taken in 2005.

Use NotePad to enter the first Java program into a file called Hello.java:

class Hello {
   public static void main(String[] a) {
      System.out.println("Hello world!"); 	
   }
}

Then compile this program in a command window with the javac command:

>c:\Program Files\Java\jdk1.5.0_09\bin\javac Hello.java

To execute the program, use the java command:

>c:\Program Files\Java\jdk1.5.0_09\bin\java -cp . Hello
Hello world!

Congratulations, you have successfully entered, compiled and executed your first Java program.

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Dr. Herong Yang, updated in 2008

Writing My First Java Program