Possible to merge in this object? (javascript)

Question

Is it possible (and if so how) to merge tags with the same value so that one tag has an array of all its galleries?

For example, begin with this:

[{
    tag: "Kings",
    galleries: [
        "2016 Kings Draft Night"
    ]
}, {
    tag: "Draft",
    galleries: [
        "2016 Kings Draft Night"
    ]
}, {
    tag: "Kings",
    galleries: [
        "2016-17 Sacramento Kings Uniforms"
    ]
}]

and end with this:

[{
    tag: "Kings",
    galleries: [
        "2016 Kings Draft Night", "2016-17 Sacramento Kings Uniforms"
    ]
}, {
    tag: "Draft",
    galleries: [
        "2016 Kings Draft Night"
    ]
}]

Any help is much appreciated. Stumped on this

ryeballar · Accepted Answer · 2016-07-03 03:56:02Z

2

You can filter() to concat() existing tag galleries, while at the same time remove the unnecessary ones.

var result = data.filter(function(item) {
  var ref = this[item.tag];
  if(!ref) {
    return (this[item.tag] = item);
  }
  ref.galleries = ref.galleries.concat(item.galleries);
}, {});

var data = [{
  tag: "Kings",
  galleries: [
    "2016 Kings Draft Night"
  ]
}, {
  tag: "Draft",
  galleries: [
    "2016 Kings Draft Night"
  ]
}, {
  tag: "Kings",
  galleries: [
    "2016-17 Sacramento Kings Uniforms"
  ]
}];

var result = data.filter(function(item) {
  var ref = this[item.tag];
  if(!ref) {
    return (this[item.tag] = item);
  }
  ref.galleries = ref.galleries.concat(item.galleries);
}, {});

document.write('<pre>' + JSON.stringify(result, 0, 4) + '</pre>');

edited Jul 3, 2016 at 3:56

answered Jul 3, 2016 at 3:34

ryeballar

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1 Comment

ElDoRado1239 Over a year ago

Not exactly clean or easy to understand for an inexperienced coder, but I really like this. Probably almost optimal as well.

KevBot · Accepted Answer · 2016-07-03 03:15:37Z

1

I'm sure there are even faster ways to do this. But here is what I came up with:

var data = [{ tag: "Kings", galleries: [ "2016 Kings Draft Night" ] }, { tag: "Draft", galleries: [ "2016 Kings Draft Night" ] }, { tag: "Kings", galleries: [ "2016-17 Sacramento Kings Uniforms" ]}]


var newData = {};
data.forEach(function(a) {
  if (!newData[a.tag]) {
    newData[a.tag] = a.galleries;
  } else {
    newData[a.tag] = newData[a.tag].concat(a.galleries);
  }
});

var complete = [];
Object.keys(newData).forEach(function(key) {
  complete.push({
    tag: key,
    galleries: newData[key]
  });
});

console.log(complete);

answered Jul 3, 2016 at 3:15

KevBot

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1 Comment

AJ Singh Over a year ago

It worked brother thank you. could not for the life of me figure that out!!

Deep · Accepted Answer · 2016-07-03 03:27:32Z

0

you can try like this.

var objA = [{
tag: "Kings",
galleries: [
    "2016 Kings Draft Night"
]
}, {
tag: "Draft",
galleries: [
    "2016 Kings Draft Night"
]
}, {
tag: "Kings",
galleries: [
    "2016-17 Sacramento Kings Uniforms"
]
}]


var result = [];

for (var property in objA) {
if (objA.hasOwnProperty(property)) {
    if (result.filter(function(e) { if( e.tag == objA[property].tag) return    e.galleries.push(objA[property].galleries[0]) }).length > 0) {
    }
    else
    {
      result.push(objA[property]);
    }

   }
  }

 console.log(result);

plunker : http://plnkr.co/edit/7AijNY4Tb4DSDaiEQEEB?p=preview

answered Jul 3, 2016 at 3:27

Deep

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Comments

ElDoRado1239 · Accepted Answer · 2016-07-03 03:42:00Z

0

Merge function :

function merge(a){
 var r = {},n = [];
 for(var d in a) 
  r[a[d].tag] = (r[a[d].tag]) ? r[a[d].tag].concat(a[d].galleries) : a[d].galleries;
 for(var d in r) n.push({'tag':d,'galleries':r[d]});
 return(n);
}

And a test :

a = [{tag: "Kings",galleries: ["2016 Kings Draft Night"]},{tag: "Draft",galleries: ["2016 Kings Draft Night"]},{tag: "Kings",galleries: ["2016-17 Sacramento Kings Uniforms"]}];
console.log(merge(a));

edited Jul 3, 2016 at 3:42

answered Jul 3, 2016 at 3:15

ElDoRado1239

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Comments

guest271314 · Accepted Answer · 2016-07-03 04:06:57Z

0

You can use .filter(), .reduce(), .map(), rest element, spread element

var arr = [{
  tag: "Kings",
  galleries: [
    "2016 Kings Draft Night"
  ]
}, {
  tag: "Draft",
  galleries: [
    "2016 Kings Draft Night"
  ]
}, {
  tag: "Kings",
  galleries: [
    "2016-17 Sacramento Kings Uniforms"
  ]
}];

var filterTags = (a, type) => a.filter(o => o.tag === type)
  .reduce((curr, next) => {
    [...curr.galleries] = [...curr.galleries, ...next.galleries];
    return curr
  });

var res = ["Kings", "Draft"].map(val => filterTags(arr, val));

console.log(res);

answered Jul 3, 2016 at 4:06

guest271314

1

Comments

Yasin Yaqoobi · Accepted Answer · 2016-07-03 04:47:26Z

0

for (var i = 0; i < obj.length-1; i++){
    var currTag = obj[i].tag;  // get first element

   for (var j = i + 1; j < obj.length; j++){ // Search for matching tags
       var newTag = obj[j].tag; 
       if (currTag === newTag){
         array1 = obj[i].galleries;  // get gallery for prevElement
         array2 = obj[j].galleries; // get gallery for curr element
         Array.prototype.push.apply(array1, array2); // merge arrays
         obj.splice(j,1); // remove the curr array from obj
       }
   }  
}

answered Jul 3, 2016 at 4:47

Yasin Yaqoobi

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