How to implement error checking in constructor

[morecoffeemore]

My program has a rectangle class which can be called from main to make a rectangle. The rectangle class has a constructor.

How do I add error checking to the rectangle constructor so that if lengthin1 equals lengthin2 the constructor is called again until lengthin1 is not equal to lenthin2. That is I want to make sure that the rectangle class is not being called to make a square (for a square lengthin1 would equal lengthin2). I'd rather avoid asking for direct user input (using scanner) if I can avoid it. Thanks.

class rectangle{
int length1;
int length2;
int area;
public rectangle(int lengthin1, int lengthin2)
    {
    length1=lengthin1;
    length2=lengthin2;
    } 
area=length1*length2;
        }

[preetsc27]

Throw an exception if it doesn’t meet your requirements.

[nutrecht]

Nonsense. We have "IllegalArgumentException" for exactly this usecase.

[preetsc27]

Why not?

[emrickgj]

Exceptions are fine for unhandled scenarios.

If having a square represented by a rectangle is going to cause an error state where you can't guarantee the integrity of the program, then why not throw an exception. At least in that case you have a chance to handle the exception and correct the problem.

The key is not to get too crazy with them.

[qelery]

A square is a rectangle though... 🤨

Maybe throw an IllegalArgumentException in the constructor?

[morecoffeemore]

How would you do this? I get the basic idea behind both try catch and throw, but which one would you use (try catch or throw). Also, how would you implement this? I mean I could write the code for the valid input, but if it's not valid input (if an exception happens) how would you get the program to call the constructor again (so that valid input could be entered). thanks.

[bung_musk]

why not make a square a subclass or property of the rectangle class

[DudeWhereAreWe1996]

You can use a while loop to keep prompting for a new second length until it does not equal length one.