如何提取对象数组中每个对象的两个元素并制作一个新元素

Question

I have an array whose length could be > 1 at any time and just keep getting bigger.

I need to extract only TWO of the values of the parent array elements and put them into a new array.

Here's the example of the base array:

{
    "strains":[
            {
                "id": 150,
                "name": "Animal Cookies (Phat Panda)",
                "label": "Animal Cookies (Phat Panda)",
                "thcpct": 14,
                "cbdpct": 19,
                "ttlpct": 33,
                "type": "Hybrid SD",
                "subtype": "Sativa Dominant",
                "bitactive": 1,
                "useradded": "jjones",
                "dateadded": "4/12/2017"
            },
            {
                "id": 110,
                "name": "Blue Dream (Pioneer)",
                "label": "Blue Dream (Pioneer)",
                "thcpct": 24,
                "cbdpct": 0,
                "ttlpct": 24,
                "type": "Sativa",
                "subtype": "None",
                "bitactive": 1,
                "useradded": "jjones",
                "dateadded": "3/27/2017"
            },
            {
                "id": 30,
                "name": "Candyland",
                "label": "Candyland",
                "thcpct": 25,
                "cbdpct": 75,
                "ttlpct": 100,
                "type": "Hybrid SD",
                "subtype": "Sativa Dominant",
                "bitactive": 1,
                "useradded": "jjones",
                "dateadded": "1/1/2017"
            },
            {
                "id": 130,
                "name": "Dragon OG (Avitas)",
                "label": "Dragon OG (Avitas)",
                "thcpct": 26,
                "cbdpct": 18,
                "ttlpct": 44,
                "type": "Hybrid SD",
                "subtype": "Sativa Dominant",
                "bitactive": 1,
                "useradded": "jjones",
                "dateadded": "4/10/2017"
            }
    ]
}

and this is what I want it to look like after the extraction:

{
    "strains":[
            {
                "id": 150,
                "label": "Animal Cookies (Phat Panda)",
            },
            {
                "id": 110,
                "label": "Blue Dream (Pioneer)",
            },
            {
                "id": 30,
                "label": "Candyland",
            },
            {
                "id": 130,
                "label": "Dragon OG (Avitas)",
            }
    ]
}

The way I've tried to do this is with push, one array equals another and still I get Push is NOT a function, or 'id' is undefined and the code stops.

This is EASY STUFF and assigning one array element to another is not difficult but why is this case so different?

I have the example code for what I've tried here:

I've tried using LODASH here:

//This is the call to the FIX_KEY function in appservice
  _.object(
     _.map(
      _.keys(allStrains.data),
         ctrlMain.appSvc.appFuncs.fix_key(/^name/, 'label')),
      _.values(allStrains.data)
  );

Here's the function in appservice:

svc.appFuncs = {
  //https://stackoverflow.com/questions/32452014/change-key-name-in-javascript-object
  //This replaces a STATIC key value for now, but can probably
  //replace any value
          fix_key: function (key, keyname) {
             return key.replace(key, keyname);
          }
}

I modified a lodash code from the Stack Overflow question in the comments.

UPDATE 1:

Andrjez, please see the end result on how I need to make this work and where I'm experiencing the problem:

             * Angular Dropdown Multi-select
             *
             * For STRAINS to select what will be in the room selected
             *
             */
            $scope.example8model = [];

            //Get the data from LOCALSTORAGE
            var getResults;
            **//I GET THE RESULTS from LOCAL STORAGE HERE**
            getResults = storageLocalService.getItemJSON("allstrains");
            **//CHECK the strains from LOCAL STORAGE**
            console.log("Strains: ", getResults.strains); //FAILS HERE!!!
            //getResults.strains is UNDEFINED but getResults HOLDS the JSON
            //EXACTLY how you made it in your example. I just changed
            //**obj** to **getResults**.



            var result = {
                //NEXT LINE FAILS: getResults.strains.map is UNDEFINED!    
                strains: getResults.strains.map(function (item) {
                    return {
                        id: item.id,
                        label: item.label
                    };
                })
            };

            console.log("All extracted Strains: ", result);

            $scope.example8model = result;

            //$scope.example8data = [
            //    {id: 1, label: "David"},
            //    {id: 2, label: "Jhon"},
            //    {id: 3, label: "Danny"}
            //];
            $scope.example8settings = {
                checkBoxes: true
            };

Here's the problem: The data in LOCAL STORAGE does NOT have double-quotes either leading or trailing. BUT...

This is what I get in the DEV CONSOLE:

Notice, no DBL QUOTE ADDED for leading or trailing:

Then when I click to the NEXT level down, DOUBLE QUOTES ARE ADDED thus messing up trying to access: getResults.strains.map()...

Finally, the resulting Error...

So, where am I going wrong?

NOTE: This is what I'm trying to achieve: MULTI-SELECT

Answer 1

Use Array.prototype.map :

var result = { 
    strains: obj.strains.map(function (item) {
        return {
          id: item.id,
          label: item.label
        }; 
    })
};

Try the snippet below to see the result:

 var obj = { "strains":[ { "id": 150, "name": "Animal Cookies (Phat Panda)", "label": "Animal Cookies (Phat Panda)", "thcpct": 14, "cbdpct": 19, "ttlpct": 33, "type": "Hybrid SD", "subtype": "Sativa Dominant", "bitactive": 1, "useradded": "jjones", "dateadded": "4/12/2017" }, { "id": 110, "name": "Blue Dream (Pioneer)", "label": "Blue Dream (Pioneer)", "thcpct": 24, "cbdpct": 0, "ttlpct": 24, "type": "Sativa", "subtype": "None", "bitactive": 1, "useradded": "jjones", "dateadded": "3/27/2017" }, { "id": 30, "name": "Candyland", "label": "Candyland", "thcpct": 25, "cbdpct": 75, "ttlpct": 100, "type": "Hybrid SD", "subtype": "Sativa Dominant", "bitactive": 1, "useradded": "jjones", "dateadded": "1/1/2017" }, { "id": 130, "name": "Dragon OG (Avitas)", "label": "Dragon OG (Avitas)", "thcpct": 26, "cbdpct": 18, "ttlpct": 44, "type": "Hybrid SD", "subtype": "Sativa Dominant", "bitactive": 1, "useradded": "jjones", "dateadded": "4/10/2017" } ] }; var result = { strains: obj.strains.map(function (item) { return { id: item.id, label: item.label }; }) }; console.log(result); 

If you wish to use es6 features:

const result = { strains: obj.strains.map(({id , label}) => ({id, label})) };

Answer 2

obj.strains = obj.strains.map(x => ({ id: x.id, label: x.label }));

If it's more than just strains, and you want to apply the same logic to each sub array:

let filtered = Object.entries(obj)
  .filter(([k, arr]) => Array.isArray(arr))
  .reduce((acc, [k, arr]) => {
    acc[k] = arr.map(x => ({ id: x.id, label: x.label }));
    return acc;
  }, {});

Answer 3

My Solution:

var test = 'label'
var results = [];
var response = strains.forEach( obj => {
    if (obj[test]) {
        results = [
            ...results,
            {
                test: obj[test]
            }
        ];
    }
});

console.log('matches', results);
//output: matches, [{test: "Animal Cookies (Phat Panda)"}, {test: "Blue Dream (Pioneer)"}, {test: "Candyland"}, {test: "Dragon OG (Avitas)"}]

Answer 4

for (n of strains) {
    n = n.filter(function(elem,index){
        return (index == "id" || index == "label")
    });
}

Something like that?