Java Constructor undefined?

Question

Ok, I am working on an assignment for school, and I set up my main class and also another class called Transaction. In my main class I have:

Transaction t = new Transaction();

And Transaction is underlined: it says that the constructor undefined. WHY?!

The Transaction class looks like this:

public class Transaction {

private String customerNumber, fName, lName, custAddress, custCity;
private int custZip, custPhone;

/** Constructor*/
public Transaction(String a, String b, String c, String d, String e, int f, int g){
    this.customerNumber = a;
this.fName = b;
this.lName =c;
this.custAddress = d;
this.custCity = e;

}

It looks like it should just work, but it's just not. Even when I plug in a bunch of variables into where I make the new Transaction object in main, it still says undefined. Somebody please help!

It seems like you need to read at least some Java 101 to get started. — Geoffrey Zheng
– Geoffrey Zheng, Commented Sep 11, 2010 at 5:30
I would suggest you to check you variable names too. Plus, if you're not using all of them, why parametrize f and g in the constructor? — Philippe Gioseffi
– Philippe Gioseffi, Commented Jan 30, 2014 at 22:19

Prasoon Saurav · Accepted Answer · 2010-09-11 05:26:22Z

9

There is no default constructor definition in your class.

When you provide the definition of at least one parameterized constructor the compiler no longer provides you the default constructor.

answered Sep 11, 2010 at 5:26

Prasoon Saurav

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Comments

makes · Accepted Answer · 2011-11-03 18:51:33Z

2

This is because you haven't declared a constructor with no arguments.

When you have no constructor defined at all, there is a default constructor with no arguments defined automatically for you.

But now that you've declared a constructor with arguments, you now need to pass them or declare another constructor with no arguments.

edited Nov 3, 2011 at 18:51

makes

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answered Sep 11, 2010 at 5:24

Tom

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1 Comment

Geoffrey Zheng Over a year ago

Constrictor... subconcious leak? :)

mskfisher · Accepted Answer · 2011-11-08 21:09:07Z

2

You need to make a default constructor (one that takes no arguments).

edited Nov 8, 2011 at 21:09

mskfisher

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answered Sep 11, 2010 at 5:29

Sanju

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Comments

JD Williams · Accepted Answer · 2010-09-11 05:39:07Z

-5

Those guys that said that you that there is no default constructor because you coded a constructor with arguments are thinking C++. That's true for C++ but not for Java. There is no such thing as a default constructor. You have to code any constructor for your class. You don't have to have a constructor if you're not going to construct any objects.

answered Sep 11, 2010 at 5:39

JD Williams

1

4 Comments

Matthew Wightman Over a year ago

In Java you do get a default constructor with no arguments if you specify no constructors.

JD Williams Over a year ago

I experimented. Are you saying that myClass mc = new myClass(); can be used if you haven't coded the no argument constructor? That didn't work when I tried it.

Matthew Wightman Over a year ago

@JD Williams: The default constructor only exists if you specify no other constructors at all, not just no constructors with no arguments. See java.sun.com/docs/books/jls/third_edition/html/… , which defines the default constructor.

JD Williams Over a year ago

Thanks for the link, Matthew. I went back to see what I had done wrong with my experiment. I do see now that it's only if no constructors are defined that a default is provided. My mistake was in sloppy reading of the problem...since he had a constructor with arguments then he needed to provide a default. If he had not coded any constructors then the compiler would provide one. Btw, I registered on the site minutes before making that first comment. Not a very good start but I do appreciate getting me understanding improved.

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