数组Array中的Javascript嵌套过滤器

Question

I have an array of objects in this format:

var full_list = [
        {
            "pid": 1,
            "items":[
                {"item_id": '9'},
                {"item_id": '10'},
                {"item_id": '12'}
            ]
        },
        {
            "pid": 2,
            "items":[
                {"item_id": '33'},
                {"item_id": '22'},
                {"item_id": '65'}
            ]
        }...
    ];

I have a tmp array which consists of objects from the full array:

 var tmp_list =  [
        {
            "pid": 2,
            "items":[
                {"item_id": '33'},
                {"item_id": '22'},
                {"item_id": '65'}
            ]
        }, {....}

I would like to filter out objects from the full list where at least one of selectedIDs values appears in the object's item's id array

var selectedIDs = {'1', '9', '45', ....};

and then add them to the tmp list.

I tried using filters but I failed to figure it out completely.

Thank you.

selectedIDs.forEach(function(id) {
                var tmp = full_list.filter(function (obj) {
                            obj.items.forEach(function (item) {
                                if (item.id === id) {
                                    console.log('found');
                                }
                            });
                        });
                        tmp_list.push(tmp);
                 });

Answer 1

You could use a hash table for the selectedID and use it for fast filtering.

 var full_list = [{ "pid": 1, "items": [{ "item_id": '9' }, { "item_id": '10' }, { "item_id": '12' }] }, { "pid": 2, "items": [{ "item_id": '33' }, { "item_id": '22' }, { "item_id": '65' }] }], tmp_list, selectedIDs = ['1', '9', '45'], selected = Object.create(null); selectedIDs.forEach(function (a) { selected[a] = true; }); tmp_list = full_list.filter(function (a) { return !a.items.some(function (b) { return selected[b.item_id]; }); }); console.log(tmp_list); 

ES6

 var full_list = [{ "pid": 1, "items": [{ "item_id": '9' }, { "item_id": '10' }, { "item_id": '12' }] }, { "pid": 2, "items": [{ "item_id": '33' }, { "item_id": '22' }, { "item_id": '65' }] }], tmp_list, selectedIDs = ['1', '9', '45'], selected = Object.create(null); selectedIDs.forEach(a => selected[a] = true); tmp_list = full_list.filter(a => !a.items.some(b=> selected[b.item_id])); console.log(tmp_list); 

Answer 2

First of all, this line in your question is wrong

var selectedIDs = {'1', '9', '45', ....};

You cannot declare arrays using {} . Instead use []

For your problem you can use a pure functional approach using Array#filter and Array#some methods to get your desired result as below:

 var full_list = [ { "pid": 1, "items":[ {"item_id": '9'}, {"item_id": '10'}, {"item_id": '12'} ] }, { "pid": 2, "items":[ {"item_id": '33'}, {"item_id": '22'}, {"item_id": '67'} ] }, { "pid": 9, "items":[ {"item_id": '33'}, {"item_id": '22'}, {"item_id": '65'} ] }, { "pid": 7, "items":[ {"item_id": '7'}, {"item_id": '22'}, {"item_id": '65'} ] } ]; var tmp_list = [ { "pid": 2, "items":[ {"item_id": '7'}, {"item_id": '22'}, {"item_id": '65'} ] } ]; function filterResult (selectedItems) { return full_list.filter(function (process) { return process.items.some(function(item){ return selectedItems.indexOf(item.item_id) > -1; }); }); } var selectedItems = ['9', '7', '22', '10']; tmp_list = tmp_list.concat(filterResult(selectedItems)) console.log(tmp_list); function flattenResults(list, selections) { return list.reduce(function (accumulator, current) { var res = current.items.filter(function(item){ return (selections.indexOf(item.item_id) > -1 && checkIfAlreadyExist()); function checkIfAlreadyExist () { return accumulator.every(function (k) { return k.item_id !== item.item_id; }); } }); return accumulator.concat(res); }, []); } console.log(flattenResults(full_list, selectedItems)); 

Answer 3

You may do like this;

 var full_list = [ { "pid": 1, "items":[ {"item_id": '9'}, {"item_id": '10'}, {"item_id": '12'} ] }, { "pid": 2, "items":[ {"item_id": '33'}, {"item_id": '22'}, {"item_id": '65'} ] } ], selectedIDs = ['1', '9', '45'], tempList = []; tempList.push(full_list.filter(f => f.items.some(o => selectedIDs.includes(o.item_id)))); console.log(tempList); 

Answer 4

I think this could be a solution.

 var full_list = [ { "pid": 1, "items": [ { "item_id": '9' }, { "item_id": '10' }, { "item_id": '12' } ] }, { "pid": 2, "items": [{ "item_id": '33' }, { "item_id": '22' }, { "item_id": '65' }] }]; var selectedIDs = ['33', '3']; var tempList = []; full_list .filter(item => item.items .some(i => selectedIDs.indexOf(i.item_id) != -1) ).forEach(item => tempList.push(item)); console.log(tempList) 

Answer 5

array1
array2

array1.filter(el=>{
   return array2.filter(el2=>{
          return el.id == el2.id
     })
})

It will take array1 and run it against the second one ... for each value.

Answer 6

Spread operator should simplify some code:

 var full_list = [ { "pid": 1, "items": [ { "item_id": '9' }, { "item_id": '10' }, { "item_id": '12' } ] }, { "pid": 2, "items": [{ "item_id": '33' }, { "item_id": '22' }, { "item_id": '65' }] }]; var selectedIDs = ['65', '6']; var tempList = []; tempList = [...tempList, ...full_list.filter(item => item.items.some(i => selectedIDs.includes(i.item_id))) ]; console.log(tempList); 

Answer 7

Looking at your job 1. There is nothing like market

obj.items.forEach(function (item) { if (item.item_id === id) { console.log('found'); return true; } return false;
});