Running our first java class

If you are starting with java we are going to create our Hello World. For this propuse you can create a new text file and  name “HelloWorld.java”, the content of the file should be

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

To execute the first class you can run in your terminal

java HelloWorld.java

Make sure that the terminal is located in the directory where you created the file. We execute our first program in java. Since java 11 if you have code in one file you can run it this way. It is important to mention that if you use this way to run java files you only can use the classes that came with the jdk.

Other way to execute the program is to compile the java file first

javac HelloWorld.java

The result of the compilation should be a HelloWorld.class. This file must be executed

java HelloWorld.java

It is important to not include the .class in the command.