[Newbies] Re: indexing into a collection
joseph.alotta at gmail.com
Wed Jul 27 00:13:48 UTC 2016
Ben, Ron, I made a small example, and it works as you said it would:
a := #( #(1 2) #(3 4)).
b := a asOrderedCollection.
b => an OrderedCollection(#(1 2) #(3 4))
c := b select: [ :i | (i first) = 3 ].
c => an OrderedCollection(#(3 4))
d := c first
d => #(3 4)
d at: 2 put: 5
d => #(3 5)
b => an OrderedCollection(#(1 2) #(3 5))
Okay, I will check my other code.
> On Jul 26, 2016, at 6:25 PM, Ben Coman [via Smalltalk] <ml-node+s1294792n4908113h52 at n4.nabble.com> wrote:
> Hi Joe,
> As Ron said, you should not be getting a copy. If you still have a
> problem, perhaps best if you post code for a complete example:
> * class definition (with just two instance variables)
> * instance variable accessor methods
> * instance creation & adding to collection
> * select statement
> * updating object
> cheers -ben
> On Wed, Jul 27, 2016 at 5:53 AM, Ron Teitelbaum <[hidden email]> wrote:
> > Hi Joe,
> > If the orderedCollection contains your object DrivingDays then select should give you the object and not a copy.
> > You don't need to add it back to the collection just update the object.
> > Check your code for anything that might be making a copy.
> > All the best,
> > Ron Teitelbaum
> > -----Original Message-----
> > From: [hidden email] [mailto:[hidden email]] On Behalf Of Joseph Alotta
> > Sent: Tuesday, July 26, 2016 3:04 PM
> > To: [hidden email]
> > Subject: [Newbies] indexing into a collection
> > Greetings,
> > I have a OrderedCollection of DrivingDays.
> > an OrderedCollection(2016-01-02| quigley s| nil|18§
> > 2016-01-03| marianos fresh| nil|5§
> > 2016-01-04| fresh thyme| nil|5§
> > 2016-01-05| panda express| nil|3§
> > 2016-01-06| peets| nil|7§
> > 2016-01-07| starbucks| nil|3§)
> > I want to select aDrivingDay object from the list by date, update it by adding mileage and places visited and put it back into the list.
> > If I #select the OrderedCollection, I get a copy of the item, not the same one in the OrderedCollection.
> > How do I select an item in the list for update?
> > Sincerely,
> > Joe.
> Beginners mailing list
> [hidden email]
> If you reply to this email, your message will be added to the discussion below:
> To start a new topic under Squeak - Beginners, email ml-node+s1294792n107673h12 at n4.nabble.com
> To unsubscribe from Squeak - Beginners, click here.
View this message in context: http://forum.world.st/indexing-into-a-collection-tp4908090p4908114.html
Sent from the Squeak - Beginners mailing list archive at Nabble.com.
-------------- next part --------------
An HTML attachment was scrubbed...
More information about the Beginners