Question

I have an object like so:

> Object
  > [e-mail]: Array[100]
  > [e-mail]: Array[4]
    > 0
       id : 132
       selected : true
    > 1
       id : 51
       selected : false

etc..

How can I use the underscore _.filter() to return back only the items where selected === true?

I’ve never had the need to go down to layers with _.filter(). Something like

var stuff = _.filter(me.collections, function(item) {
    return item[0].selected === true;
});

Thank you

Answer 1

If you want to pull all array elements from any e-mail address where selected is true, you can iterate like so:

var selected = [];

for (email in emailLists) {
    selected.concat(_.filter(emailLists[email], function (item) {
        return item.selected === true;
    }));
}

If you only want to pull the arrays where all elements are selected, you might instead do something like this:

var stuff = _.filter(me.collections, function(item) {
    return _.all(item, function (jtem) { 
        jtem.selected === true;
    });
});