2022.2


Selector Paragraph
before script
execution
Paragraph after script
execution
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filter()
filter(callback)
Returnsasubsetofaset.Allelementsforwhichthecallbackfunctionreturnstruewillbeincludedin
theresult.
callback
Afunctionusedasatestforeachelementintheset.Filter()passestheiterationindexandthecurrent
elementtothecallbackfunction.Inthescopeofthecallbackfunction,thisreferstothecurrentele-
ment.
Example
Theselectorofthefollowingscriptisli(listitem),sotheresultsobjectcontainsalllistitemsinthe
template.Thescriptsfiltersthethirdandsixthlineitemsfromtheresults,takingadvantageofthe
indexthatispassedtothefilterfunction,andcolorsthemred.Itusesthemodulusoperator(%)to
selecteveryitemwithanindexvaluethat,whendividedby3,hasaremainderof2.(Theindexstarts
countingatzero.)
results.filter(function(index) {
return index % 3 === 2;
}).css( "background-color", "red" );
filter(selector)
Returnsasubsetofaset.Allelementsmatchingtheselectorwillbeincludedintheresult.
Thedifferencebetweenresults.filter(selector)andquery(selector, results)isthat
query()searchesthroughouttheentireresultswhilefilter()onlytakesthetop-levelelementsinto
account.
selector
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