comparing objects in a collection
Torge at gmx.de
Torge at gmx.de
Mon Feb 3 10:37:53 UTC 2003
I think your mistake lies in what you expect to happen.
The comparison wil be evaluated for every element in the collection
and thus the transcipt will tell you (n-1) times that the element is
not in the collection (where n is the number of elements in the collection)
and only once will show the element.
To make it clearer i'd change the code to:
(assuming you do this in an inspector where self is bound to the
self do:[:element | element number == accountNumber
ifTrue:([Transcript show: element;cr])
ifFalse:([Transcript show: element, ' is not the desired element';cr])].
Of course you could also write:
element number == accountNumber]
ifNone:['no such element']).
03.02.2003 05:44:13, Janet Abdul-Karim <jn_karim at yahoo.com> wrote:
> > findAccount: accountNumber
> > "Find the account with the argument number"
> > self do:[:element | element number == accountNumber
> > ifTrue:([Transcript show: element;cr])
> > ifFalse:([Transcript show: 'No such account exists in this
> My guess is that you want to use #= (equality) not #== (identity
> equality). Numbers above a certain size are represented in such a way
> that they are not the same object even when they are the same number, and
> so they are #= but not #==. For example:
> 12 = 12 "true"
> 12 == 12 "true"
> (12 raisedTo: 10) = (12 raisedTo: 10) "true"
> (12 raisedTo: 10) == (12 raisedTo: 10) "false"
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