用简单的英语，我如何使用图书馆？

Question

I am trying to use Standard Library from Princeton, I used their downloader that automatically installs the library into Intellij, but when I try to use one of their functions, like StdOut.print() I get an error

This is the code:

public class Main {
    public static void main(String[] args) {
    StdOut.print("Example");
    }
}

When trying to run this program I get the error message:

Error:(5, 9) java: cannot find symbol
  symbol:   variable StdOut
  location: class wsu.edu.Main

How do I make it so that I can use this library?

I've heard a lot of confusing words trying to solve this issue, so please give it to me in plain English, assume I'm an idiot that knows nothing about JAR, class, classloader, classpath, package or default package.

Is there something I can add to my code that will make this work?
Do I add a file to my folder? Can I also see an example?

Answer 1

Assuming you are using IntelliJ, open the project structure (icon on the top bar) in the Library section add the jar file. Now your IDE can use it. Next, import it into your class using the import directive (above the class declaration). Now you should be able to use it.

an example might be like this

import stdlib.StdIn;
public class Test
{
 public static final int Main(String[] args)
 {
    if(StdIn.hasNextChar())
    {
       //do something
    }
 }
 
}