Re: opposite of AppendTo

*To*: mathgroup at smc.vnet.net*Subject*: [mg124365] Re: opposite of AppendTo*From*: Szabolcs Horvát <szhorvat at gmail.com>*Date*: Tue, 17 Jan 2012 05:57:13 -0500 (EST)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com*References*: <jf13lb$5ma$1@smc.vnet.net>

On 2012.01.16. 14:02, burke wrote: > AppendTo[s,e] appends "e" to "s" and then RESETS "s". How does one > delete or remove an element "e" from a list "s" and then RESET "s"? > The _reset_ is my problem. I want to be able to add and delete > elements of a list (a list of graphical elements with very low > opacity). I can "appendto" the list at will but am unable to delete > elements (using Delete, DeleteCases, Except, Select, etc.). Deleting > "e" from "s" is easy enough, but resetting "s" seems impossible. > Help!! > You can always re-assign the list, as in s = Most[s]; In Mathematica functions almost never modify their arguments directly. They return a modified copy instead. Exceptions are Set and AppendTo/PrependTo, which do modify the argument. -- Szabolcs Horvát Mma QA site proposal: http://area51.stackexchange.com/proposals/37304