how to insert values into the array in javascript

Question

I want to insert the values from one array to another array if the values matched.

These are my arrays.

var names = [{key: 'Apple'}, {key: 'Dell'}, {key: 'Xitrix'}];
var data = [
     {enum_name:'Apple', date:'2000-12-15', accomp: 12},
     {enum_name:'Dell', date:'2000-12-15', accomp: 8},
     {enum_name:'Apple', date:'2000-12-16', accomp: 12},
     {enum_name:'Xitrix', date:'2000-12-16', accomp: 12},
     {enum_name:'Dell', date:'2000-12-17', accomp: 8},
     {enum_name:'Xitrix', date:'2000-12-17', accomp: 12},
];

Then i want to insert data.date and data.accomp into the array names with a specific key (e.g. attrib: [arrays];

I have this code but it doesn't insert all the matched data to the key attrib.

    var counts = 0;
    _.each(names, function(v, k){
        _.each(data, function(val, key){
            if(v.key == val.enum_name){
                var date = val.date;
                var accomp= val.accomp;

                names[k].attrib= [[date, accomp]];
                console.log(counts);
                counts++;
            }
        });
        counts = 0;
        //names[k]['values'] = 'test';
    });

i want an output like this.

 names = [
    {key: 'Apple', attrib: [['2000-12-15', 12], ['2000-12-16', 12]]}, 
    {key: 'Dell', attrib: [['2000-12-15', 8], ['2000-12-17', 8]]},
    {key: 'Xitrix', attrib: [['2000-12-16', 12], ['2000-12-17', 12]]}
 ];

{'2000-12-17', 12} That is invalid syntax, what do you actually want there? — CertainPerformance
– CertainPerformance, Commented Jun 29, 2018 at 1:35
There's no jQuery here. You're using either underscore.js or lodash. Please edit the question to specify. — Barmar
– Barmar, Commented Jun 29, 2018 at 1:41

CertainPerformance · Accepted Answer · 2018-06-29 01:49:29Z

3

Try using reduce into an object indexed by enum_name with an array of dates and accomps, and then get that object's values, no library needed, and with less runtime complexity:

var names = [{key: 'Apple'}, {key: 'Dell'}, {key: 'Xitrix'}];
var data = [
   {enum_name:'Apple', date:'2000-12-15', accomp: 12},
   {enum_name:'Dell', date:'2000-12-15', accomp: 8},
   {enum_name:'Apple', date:'2000-12-16', accomp: 12},
   {enum_name:'Xitrix', date:'2000-12-16', accomp: 12},
   {enum_name:'Dell', date:'2000-12-17', accomp: 8},
   {enum_name:'Xitrix', date:'2000-12-17', accomp: 12},
];
console.log(Object.values(
  data.reduce((a, { enum_name: key, date, accomp }) => {
    if (!a[key]) a[key] = { key, attrib: [] };
    a[key].attrib.push([date, accomp]);
    return a;
  }, {})
));

answered Jun 29, 2018 at 1:49

CertainPerformance

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Comments

Barmar · Accepted Answer · 2018-06-29 02:33:00Z

1

First start by creating an object containing the names elements, keyed by the key property, so it's easy to find the element for a specific key, and add the attrib property to them.

Lodash:

var namesObj = _.forEach(_.keyBy(names, 'key'), n => n.attrib = []);

Underscore.js:

var namesObject = _.each(_.indexBy(names, 'key'), n => n.attrib = []);

Then you can loop over the data and push the attributes onto the appropriate object.

_.each(data, ({enum_name, date, accomp}) => 
    namesObj[enum_name].attribs.push([date, accomp])
);

edited Jun 29, 2018 at 2:33

answered Jun 29, 2018 at 1:53

Barmar

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3 Comments

p3ac3 Over a year ago

is there a _.keyBy function in underscore?

Barmar Over a year ago

it's called _.indexBy in underscore.js.

p3ac3 Over a year ago

names is Object cannot be .forEach

Tính Ngô Quang · Accepted Answer · 2018-06-29 02:01:44Z

Underscore where filter

Plz Try this code: []

  var names = [{ key: 'Apple' }, { key: 'Dell' }, { key: 'Xitrix' }];
  var data = [
    { enum_name: 'Apple', date: '2000-12-15', accomp: 12 },
    { enum_name: 'Dell', date: '2000-12-15', accomp: 8 },
    { enum_name: 'Apple', date: '2000-12-16', accomp: 12 },
    { enum_name: 'Xitrix', date: '2000-12-16', accomp: 12 },
    { enum_name: 'Dell', date: '2000-12-17', accomp: 8 },
    { enum_name: 'Xitrix', date: '2000-12-17', accomp: 12 }
  ];
  // new array
  var new_data = [];
  // loop names
  _.each(names, function (v) {
    // init new obj
    var obj = { key: v.key, attrib: [] };
    // find by underscore with key of names & enum_name of data
    var finds = _.where(data, { enum_name: v.key });
    // if using lodash then change to _.find:
    // var finds = _.find(data, { enum_name: v.key });
    // loop finds
    _.each(finds, function (value) {
      // add attrib
      obj.attrib.push([value.date, value.accomp]);
    });
    // add obj to new array
    new_data.push(obj);
  });
  console.log(new_data);

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