Having lots of parameters in a constructor

Question

Is it wrong to have a lot of parameters inside a constructor? Like 10 to 15 parameters? Because I was designing a class where a constructor will have lots of parameters, for

Answer 1

You could decompose Person into Name and Contact.

public class ComposedPerson {
    private Name name;
    private int age;
    private Contact contact;

    public ComposedPerson(Name name, int age, Contact contact) {
        this.name = name;
        this.age = age;
        this.contact = contact;
    }

    public static void main(String... args) {
        Name name = new Name("John");
        Contact contact = new Contact("12345", "john@doe.com");
        ComposedPerson person = new ComposedPerson(name, 45, contact);
   }

Sample Name. See how I use a telescoping constructor to allow for optional arguments.

public class Name {
    private String fName;
    private String lName;
    private String mInitial;

    public Name(String fName) {
        this(fName, null, null);
    }

    public Name(String fName, String lName) {
        this(fName, lName, null);
    }

    public Name(String fName, String lName, String mInitial) {
        this.fName = fName;
        this.lName = lName;
        this.mInitial = mInitial;
    }
}