thx fadden for the info. On Wed, Apr 29, 2009 at 1:19 PM, fadden <[email protected]> wrote:
> > On Apr 29, 10:44 am, Kent Yip <[email protected]> wrote: > > a switch statement is made for nested if statements. > > Actually it's not. Both Java and Dalvik have "sparse" and "packed" > switch instructions at the bytecode level. You can read about them in > the Dalvik bytecode documentation in dalvik/docs/dalvik-bytecode.html > (packed-switch/sparse-switch, corresponding to tableswitch/ > lookupswitch in Java). > > > switch statement is greate if you have a bunch of selections, to make a > > switch statement perform better you have to look at what user will likely > > selection the most, and implement that case on the top most case in the > > switch. Accessing that case will be faster than accessing cases at lower > end > > of the switch statement. > > Not really. For a "packed" switch, which is essentially a goto table, > everything is the same speed. For a "sparse" switch, the VM can > either do a linear search or a binary search through the table, > because the entries are sorted by the "case" value. Note also that > the sorting makes rearranging entries in the source code meaningless. > > > > --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Android Beginners" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/android-beginners?hl=en -~----------~----~----~----~------~----~------~--~---
