Requirements for Behavior

Also, we need a constructor to create objects from the class, so we must decide what the constructor should do. It seems reasonable that it should create a new checking account and initialize it with the account number, the account holder's name, and starting balance.

Now we have a fair idea about what the class looks like:

• Data
  • Account number.
  • Name of account holder.
  • Current balance.
• Constructor
  • Create the object; initialize the three data items.
• Methods
  • Accept a deposit.
  • Process a check.
  • Get the current balance.

For a large project, creating specifications is hard because objects interact with perhaps hundreds of other objects. In this example program, objects interact only with main().