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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple><div class=WordSection1><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Hi Gary,<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>This is a good question.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>The code is probably lazily instantiating the variable so that it can be used somewhere else. If the class variable was private to the class and not intended to be used by another class and you were only planning on calling it from the class side then it kinda works. If not; you plan to have an instance call the class variable, or another class needs access to this Class variable, then you need some sort of accessor.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Have a look at SmalltalkImage class variable StartUpList. There is no public accessor for it. There are values in it. Can you find a way to access that list and see what is in it?<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>You can write code on the class side that references StartUpList (press the class variables button to see the methods that do that, or even highlight StartUpList in a class method of that object and select: Inspect.) but can you find another way?<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>In many cases you need to access the class variable to get information that is relevant to all the class instances, or to get a single class instance (MyObject class > myDefaultInstnace) from another class so class variable accessors are required.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Ron Teitelbaum<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'> <o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><div style='border:none;border-left:solid blue 1.5pt;padding:0in 0in 0in 4.0pt'><div><div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0in 0in 0in'><p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>From:</span></b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'> beginners-bounces@lists.squeakfoundation.org [mailto:beginners-bounces@lists.squeakfoundation.org] <b>On Behalf Of </b>Gary Dunn<br><b>Sent:</b> Monday, February 28, 2011 3:07 PM<br><b>To:</b> Squeak Beginners<br><b>Subject:</b> [Newbies] Returned values<o:p></o:p></span></p></div></div><p class=MsoNormal><o:p> </o:p></p><p>While studying DBus code I came across a method that appears to set a class variable and return the value. In DBusConnection>> sessionBus<o:p></o:p></p><p> ^SessionBus := self getBus: 0 from: SessionBus<o:p></o:p></p><p>and SessionBus is a class variable. Why return the value? Why not have the sender examine the value of SessionBus? Is it only a matter of style or is this more efficient?<o:p></o:p></p><p>Gary Dunn<br>Open Slate Project<br><a href="http://openslate.org">http://openslate.org</a><o:p></o:p></p></div></div></body></html>