Not sure where/what my error is.

I have two classes: Person and PersonDemo.
Person holds all the methods, etc, etc, whilst PersonDemo is as named, just for a demo.
However, PersonDemo throws up a lot of errors in my Eclipse console, but won't

Code Java:

---

public class Person {
 
	String forename;
	String surname;
	int age;
 
	public String getName(Person nameToGet) {
		return forename + surname;
	}
 
	public Person(Person ID, String createdForename, String createdSurname, int createdAge) {
		this.forename = createdForename;
		this.surname = createdSurname;
		this.age = createdAge;
	}
 
	public void printPersonsInfo(Person infoToGet) {
		System.out.println("Name = "+getName(infoToGet)+"; Age = " + infoToGet.age);
	}
 
}

---

^No errors in that class.

Code Java:

---

public class PersonDemo {
	Person(johnSmith001, "John", "Smith", 43);//Error here, on "Person("
 
	public static void main(String args[]) {
		printPersonsInfo(johnSmith001);//Error here, on "johnSmith001"
	}
 
}

---

^I get errors on lines 2 and 5.

Upon running the demo, "Name = John Smith; Age = 43" should be printed into the console.

Move the first line inside of main. Then at the beginning of that line, declare a Person variable, and add the new keyword (because that is how you create new objects when calling constructors)

Person myPerson = new (what you already have goes here).

Then when you call printPersonsInfo, you need to use your reference to the Person object you just created

myPerson.printPersonsInfo(...)

Person(johnSmith001, "John", "Smith", 43);//Error here, on "Person("

Person p = new Person(Person x, "John", "Smith", 43);

Ok, you don't have a variable called ID.

Code java:

---

public class Person {
	String forename;
	String surname;
	int age;
 
	public String getName(Person nameToGet) {
		return forename + " " + surname;
	}
 
	public Person(String createdForename, String createdSurname, int createdAge) {
		this.forename = createdForename;
		this.surname = createdSurname;
		this.age = createdAge;
	}
 
	public void printPersonsInfo() {
		System.out.println("Name = "+getName(this)+"; Age = " + this.age);
	}
}

---

Code java:

---

public class PersonDemo {
	public static void main(String args[]) {
		Person johnSmith001 = new Person("John", "Smith", 43);
		johnSmith001.printPersonsInfo();
	}
}

---

Now if I was to create a random Person object (via the program) how would I do it? (I wanted the object's name to derive from their first name and last name.

Your methods don't need to take in a Person object as an argument...... They already have a reference to the person in the "this" variable (or you can just call getName(), and directly access the age variable

What exactly do you mean by a random person?

Let's see what this does:

Code java:

---

 
public class Person {
 
   private  String forename;
   private  String surname;
    private int  age;
    private String personID;
   private String name;
   public Person(String personID, String createdForename, String createdSurname, int createdAge) {
        this.forename = createdForename;
        this.surname = createdSurname;
        this.age = createdAge;
        this.personID = personID;
 
setAge(createdAge);
setPersonID(personID);
setName(createdForename, createdSurname);
    }
 
public void setPersonID(String personID2)
{
personID = personID2;
}
 
public String getPersonID()
{
return personID;
}
 
public void setForename(String forename2)
{
forename = forename2;
}
 
public String getForename()
{
return forename;
}
 
public void setSurname(String surname2)
{
surname = surname2;
}
 
public String getSurname()
{
return surname;
}
 
public void setAge (int age2)
{
age = age2;
}
 
public int getAge()
{
return age;
}
 
public void setName(String aForename, String aSurname)
{
name = aForename + " " + aSurname;
setForename(aForename);
setSurname(aSurname);
}
 
public void setName2()
{
name = getForeName() + " " + getSurname();
 
}
 
 
    public String getName() {
        return name;
    }
 
 
 
    public void printPersonsInfo() {
        System.out.println("Name = "+getName()+ ";
  Age = " + infoToGet.age);
    }
 
}

---

Code java:

---

public class PersonDemo {
 
 
    public static void main(String args[]) {
    Person p = new  Person("johnSmith001", "John", "Smith", 43);
   p.printPersonsInfo();
    }
 
}

---

Thankyou Javapenguin! It worked, with a bit of tweaking!

Do you have any idea how I could list all of the people created so far?

The people's name or the Person themselves?

There is a class called ArrayList<aClass> which works like an array in that it uses arrays internally but creates new arrays when it exceeds a certain size so that it can expand.

Assuming you want the names, you could do this(remember to import java.util.*)

Code java:

---

 
ArrayList<String> aList = new ArrayList<String>();
 
// for every person do this(remember index starts at 0)
 
String str = p.getName();
 
aList.add( index, str);
 
// when you are done
 
String str2 = aList.toString();
 
System.out.println(str2);
 
// that should get you a list, separated by commas, of all the names of the people you've added
// but they won't be in alphabetical order unless you add them all that way

---

If you do want alphabetical order, and as long as you don't have duplicates, you can

Code java:

---

TreeSet<String> tSet = new TreeSet<String>();
 
// for each person
String str = p.getName();
tSet.add(str);
 
// when done
 
String str2 = tSet.toString();
 
System.out.println(str2);

---

instead, but you cannot have duplicates.

For the second one, where would I add that? When the person is created?
Silly me, I see now :)
Thanks, I'll test it now!