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().