On Sunday, June 27, 2021 at 11:28:50 AM UTC-7 History Buff wrote: > I don't understand why a 0 in the butlast operator would yield no results >
The butlast[] operator is defined in this shadow tiddler: https://tiddlywiki.com/#%24%3A%2Fcore%2Fmodules%2Ffilters%2Flistops.js Here's the javascript code from that tiddler: exports.butlast = function(source,operator,options) { var count = $tw.utils.getInt(operator.operand,1), results = []; source(function(tiddler,title) { results.push(title); }); return results.slice(0,-count); }; The first line gets the operand value, defaulting to 1. The next 4 lines copy the entire list of items into a results array The last line uses the javascript slice() function to remove items from the results array and then return that array Here's the documentation for the javascript slice() function: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/slice Note the description of the "end" parameter: Zero-based index before which to end extraction. slice extracts up to *but not including* end. Thus, when you used butlast[0], the filter code invokes slice(0,-0), i.e., "*starting from the first item up to but not including the first item* " which results in *no items* being returned. enjoy, -e -- You received this message because you are subscribed to the Google Groups "TiddlyWiki" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/tiddlywiki/c1f40a73-746d-4c39-89b9-6786c9caee0fn%40googlegroups.com.
