filtering a collection in jQuery expression

Question

I am reading about filtering values in jQuery, and I passed on this example:

myvalues = $("div.myvalues");
myvalues.filter(function(index){
    return !!$(this).val().length;
});

I am wondering what does the !!$(this).val().length; mean? I know that ! is flipping the operator to false, and !! is flipping it again to true, but what's the idea?

http://stackoverflow.com/questions/784929/what-is-the-not-not-operator-in-javascript — j08691, Dec 29 '14 at 21:41

score 0 · Accepted Answer · answered Dec 29 '14 at 21:44

0

this return !!$(this).val().length; will filter out or give every element that doest have value attribute set. of course which means value length will be zero a false when checked with !!

answered Dec 29 '14 at 21:44

A.B

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So the filter method will use the returned true/false by the !! to apply the filters aha. :D thanks. – Brittany Rutherford Dec 29 '14 at 22:02
@BrittanyRutherford yeah , my pleasure :) where there will be true it keep those and where false it will remove – A.B Dec 30 '14 at 02:21

filtering a collection in jQuery expression

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