General computer language, syntax question.

jonas.thornvall at gmail.com jonas.thornvall at gmail.com
Mon Feb 29 08:56:52 EST 2016


Den måndag 29 februari 2016 kl. 14:45:37 UTC+1 skrev jonas.t... at gmail.com:
> I have a problem programming uniform networks, "x nodes with y links" that turn out to be really hairy to solve for me and i feel i really lack the programming features 
> 
> "Actually i program in javascript" but the problem seem general for all programming languages including Pyhton.
> 
> For a beautiful solution it would require "If in list/array return boolean" "If not in list/array return boolean". 
> 
> But there is no such feature Python nor Javascript, so instead i set boolean value "inlist" to false and loop thru, to see if it is already in list. If not it is added to list. 
> 
> So if the current node i generate links for is x and i try to generate a link to  node z, and z's links exhausted i will add it to exhausted list.
> 
> And if there is node-x exhausted entries in list, well then script should break because it will lock into a cycle. The cyclic lockup is due to only a subset of the networks on the form (links*deep)+1=nodes is possible.
> 
> So what i need is to know howto write "if list/array ***empty*** do {something}"
> 
> I sure know howto check if an array have 1 element 2,3,4 but how do you check for empty.
> 
> I think it is crazy that you can not do general comparissons of the type 
> If in list/array
> If not in list/array
> 
> But it is even more crazy that you can not check if list/array is empty, that is just madness.

I mean for for example Javascript
if (typeof array[index] !== 'undefined' && array[index] !== null) {
or this one
if (array[index] != null) {

I mean how do they come up with such convoluted syntax, do they pull it out of ass? Well one can always say it is needed because undefined not equal to null.

But would not if (array[index]==empty) suffice and be alot clearer?





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