No real leeway with the parens, useful though to force the correct values to be evaluated first though.
On Sun, Jan 27, 2013 at 11:53 AM, Mike Bonner <bonnm...@gmail.com> wrote: > ifs are evaluated left to right, though there is some leeway using parens. > > As to your question though, yes putting slower evals at the end of a > string of ands and ors does save time if the if fails before the slow parts. > > Did the following in a button to test. Just change one of the first > conditions to be false and the long myfunc call is never hit. Placed > parens around the myfunc() to demonstrate that they don't give precedence > in this situation. > > *on* mouseUp > > *if* 1 is 1 and 2 is 2 and (myfunc()) *then* *put* "It's all true" > > *end* mouseUp > > > *function* myFunc > > *repeat* 10000 times > > *put* random(10) > > *end* *repeat* > > *if* random(2) is 1 *then* > > *return* true > > *else* > > *return* false > > *end* *if* > > *end* myFunc > > > > On Sun, Jan 27, 2013 at 11:39 AM, Peter Haworth <p...@lcsql.com> 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
