One situation when the order of evaluation is important is if you have conditions that limit the scope of a general handler, eg:
if "field" is in the target and the locktext of the target = true then… In this case the first clause is evaluated first, and if the target is something other than a field, the second clause is skipped and you avoid throwing an error. With the clauses switched in order, you throw an error if the target is, eg, a button. I used to nest if statements: if "field" is in the target then if the locktext of the target = true then… ... until I realized I could do it all in one line. -- Peter Peter M. Brigham pmb...@gmail.com http://home.comcast.net/~pmbrig On Jan 27, 2013, at 1:39 PM, Peter Haworth wrote: > Musings about complex if statements on this Sunday morning.... > > Lets say you have a complex if statement with 4 conditions that must all be > true. Is there any advantage, other than personal preference/style, to: > > if cond1 and cond2 and cond3 and cond4 then..... > > or > > if cond1 then > if cond2 then > if cond3 then > if cond4 then... > > In either case, as soon as a condition evaluates to false, none of the rest > are evaluated, right? If so, then always best to put the conditions that > take the longest to evaluate further down the list, for example perhaps an > SQL SELECT statement that might take a while to execute? But then what if > some of the conditions are in parens, for example: > > if cond1 and cond2 and (cond3 and cond4) then.... > > The manual says the grouping operator (parens) has the highest precedence > so does this mean (cond3 and cond4) will be evaluated before cond1 and > cond2? > > Just curious. > > > Pete > lcSQL Software <http://www.lcsql.com> > _______________________________________________ > use-livecode mailing list > use-livecode@lists.runrev.com > Please visit this url to subscribe, unsubscribe and manage your subscription > preferences: > http://lists.runrev.com/mailman/listinfo/use-livecode _______________________________________________ use-livecode mailing list use-livecode@lists.runrev.com Please visit this url to subscribe, unsubscribe and manage your subscription preferences: http://lists.runrev.com/mailman/listinfo/use-livecode
