Problem with a output

I created a code with a binary tree and it compiles perfectly. However, when I run it nothing prints out. I had been on this for hours now and I am burnt out. Thank you in advance.

Code #1

Code:

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import java.io.*;
import java.lang.*;
import java.util.*;
import java.util.ArrayList;

public class FitopiaVer2
{
  ArrayList<MembershipNode> members;
  protected MembershipNode root;
  public FitopiaVer2()
  {
    members = new ArrayList<MembershipNode>();
    root = null;
  }
  public void insert(int element, String n)
  {
    MembershipNode mem = root, prev = null;
    while(mem != null)
    {
      prev = mem;
      if(mem.key < element)
        mem = mem.right;
      else mem = mem.left;
    }
    if (mem == null)
      mem = new MembershipNode(element, n);
    else if(prev.key < element)
      prev.right = new MembershipNode( element, n);
    else prev.left = new MembershipNode(element, n);
  }
  public void join(MembershipNode member)
  {
    members.add(member);
  }
  public int numberOfMembers()
  {
    return members.size();
  }
}

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Code # 2

Code:

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public class MembershipNode
{
  protected int key;
  protected String name;
  protected int month;
  protected int membershipNumber;
  protected MembershipNode left, right;
 
  public MembershipNode()
  {
    left = right = null;
  }
 
  public MembershipNode(int ele, String name)
  {
    this(ele, name, null, null);
  }
 
  public MembershipNode(int ele, String Name, MembershipNode l, MembershipNode r)
  {
    key = ele;
    this.name = Name;
    left = l;
    right = r;
  }
 
  public void open()
  {
    System.out.print(key + " ");
  }
 
  public String toString()
  {
    return " " + key + " " + name;
  }
  MembershipNode(String name, int month, int membershipNumber)
  {
    if(month >= 1 && month <= 12)
  {
    this.name = name;
    this.month = month;
    this.membershipNumber = membershipNumber;
  }
  else
  {
    System.out.println ("Invalid month (1, 12):" + month);
  }
}
}

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Code # 3

Code:

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public class FitopiaVer2Demo
{
  private static FitopiaVer2 club;
 
  public static void main(String[] args)
  {
  club = new FitopiaVer2();
  }
 
  public void demo()
  {
    club.join(new MembershipNode("Victor", 1, 7));
    club.join(new MembershipNode("Sydney", 5, 2));
    club.join(new MembershipNode("Bobby", 2, 4));
    club.join(new MembershipNode("Candy", 4, 6));
    club.join(new MembershipNode("David", 11, 8));
    System.out.println("Fitopia has " + club.numberOfMembers() + "members.");
  }
}

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Quote:

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However, when I run it nothing prints out.

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Yes, nothing prints out.

Code:

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public static void main(String[] args)
  {
  club = new FitopiaVer2();
  }

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You create a club and then ... nothing. The program just ends at that point.

Quote:

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Originally Posted by pbrockway2

Yes, nothing prints out.

Code:

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public static void main(String[] args)
  {
  club = new FitopiaVer2();
  }

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You create a club and then ... nothing. The program just ends at that point.

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Oh man, I was just too zoned out. I can't believe I made that much of an obvious mistake. Sorry I was just too tired, I'll fix it in the morning. Hopefully it will run and print. Thank you.

Yeah, sleeping on a problem is often productive. Good luck!