2.8XX Program execution – other stuff

usingAccount: obj
   aClerk: obj
      handle:
         newBalance := account_1010.deposit(100)   
         -"-
   account_1010: obj
      -"-
      deposit(amount: var float):
-->      balance := balance + amount
      -"-
   aClerk.handle

Generation of objects – OLD – SKIP

Jeg lavede først denne her udgave men lavede så den ovenfor, som jeg synes er bedre. Så skip dette her afsnit.

In the next snapshots, we show the generation of the objects in the diagram.

First usingAccount is generated from main.
Then clerk is generated from usingAccount; clerk is is declared using obj, which means that its is generated as part of the generation of usingAccount.
Then generation of clerk returns to usingAccount – the dotted arrow represents a return to the caller.
The account_1010 is generated from usingAccount followed by a return to usingAccount
Finally the generation of usingAccount returns to main and generation of usingAccount with local objects clerk and account_1010 is completed.

Snapshot after main has generated usingAccount.

Snapshot after usingAccount has generated clerk.

Snapshot after return of generation of clerk.

Snapshot after usingAccount has generated account_1010.

Snapshot after return of generation of account_1010.

Snapshot after return of generation of usingAccount.

Execution of statements -OLD

The next snapshots shows how the execution of statements in usingAccount takes place. As mentioned before, the line with arrow with no method from main to usingAccount illustrates execution of the statements in usingAccount. The snapshot is before invocation of clerk.handle.

The next snapshot show how execution of handle takes place. First account.deposit is invoked followed by yet another deposit; invocation of addInterest; invocation of withdraw and finally invocation of print.