Easiest way to interate over a complex JSON object via Javascript

Question

I'm consuming JSON data that has a bit of a weird structure for example:

{
    "RESULT": 
    {
        "COLUMNS": ["ID","name","ENABLED","perms","vcenabled","vcvalue","checkenabled","checkvalue","indxenabled","indxvalue"],
        "DATA": [
                    [7,"Site-A", 1, "1,2", 1, 1, 1, 0, 0, 0],
                    [15,"Site-B", 1, "1,2,3,4", 1, 1, 1, 0, 0, 0]
        ]
    },
    "ERROR": 0
}

I would like to create some JavaScript that would restructure this data to proper JSON structures so that the "Column" array values become the keys for the "DATA" array's values. So after a JS process is run the data resembles the following:

[
  {"ID":7,"name":"Site-A","ENABLED":1,"perms":"1,2","vcenabled":1,"vcvalue":1,"checkenabled":1,"checkvalue":1,"indxenabled":1,"indxvalue":1},
  {"ID":15,"name":"Site-B","ENABLED":1,"perms":"1,2","vcenabled":1,"vcvalue":1,"checkenabled":1,"checkvalue":1,"indxenabled":1,"indxvalue":1}

]

What are the JavaScript best practices for accomplishing the JSON restructuring? Could I accomplish this task using a JS framework like JQuery, Foundation JS, ect... ?

Answer 1

newjson is your new object, j is your json,

code is very fast as it caches the legth and don't uses push.

And as it's pure javascript it's faster than all the libraries.

var j={
 "RESULT":{
  "COLUMNS":[
   "ID",
   "name",
   "ENABLED",
   "perms",
   "vcenabled",
   "vcvalue",
   "checkenabled",
   "checkvalue",
   "indxenabled",
   "indxvalue"
  ],
  "DATA":[
   [7,"Site-A", 1, "1,2", 1, 1, 1, 0, 0, 0],
   [15,"Site-B", 1, "1,2,3,4", 1, 1, 1, 0, 0, 0]
  ]
 },
 "ERROR": 0
}

var newjson=[],d=j.RESULT.COLUMNS.length;
for(var a=0,b=j.RESULT.DATA.length;a<b;a++){
 for(var c=0,tmpObj={};c<d;c++){
  tmpObj[j.RESULT.COLUMNS[c]]=j.RESULT.DATA[a][c];
 }
 newjson[a]=tmpObj;
}

console.log(newjson);

based on Bergi's response u can also use the while-- loop.

var orig={
 "RESULT":{
  "COLUMNS":[
   "ID",
   "name",
   "ENABLED",
   "perms",
   "vcenabled",
   "vcvalue",
   "checkenabled",
   "checkvalue",
   "indxenabled",
   "indxvalue"
  ],
  "DATA":[
   [7,"Site-A", 1, "1,2", 1, 1, 1, 0, 0, 0],
   [15,"Site-B", 1, "1,2,3,4", 1, 1, 1, 0, 0, 0]
  ]
 },
 "ERROR": 0
}

var formatted = [],
data = orig.RESULT.DATA,
cols = orig.RESULT.COLUMNS,
l = cols.length,
f = data.length;

while (f--) {
  var d = data[f],
      o = {},
      g = l;
  while (g--) {
    o[cols[g]] = d[g];
  }
  formatted[f] = o;
}

Answer 2

Using Underscore, it's a one-liner:

var formatted = _.map(orig.RESULT.DATA, _.partial(_.object, orig.RESULT.COLUMNS));

With plain javascript (less elegant but faster), it would be

var formatted = [],
    data = orig.RESULT.DATA,
    cols = orig.RESULT.COLUMNS,
    l = cols.length;
for (var i=0; i<data.length; i++) {
    var d = data[i],
        o = {};
    for (var j=0; j<l; j++)
        o[cols[j]] = d[j];
    formatted.push(o);
}

Answer 3

you can use underscore Array functions for this task

http://underscorejs.org/#arrays

uusing the object function would be helpful http://underscorejs.org/#object

from the documentation : _.object(list, [values]) Converts arrays into objects. Pass either a single list of [key, value] pairs, or a list of keys, and a list of values ..the example:

_.object(['moe', 'larry', 'curly'], [30, 40, 50]);
 => {moe: 30, larry: 40, curly: 50}

here is the JSfiddle with the solution http://jsfiddle.net/rayweb_on/kxR88/1/

and the code looks like this for this specific scenario.

 var plain = {
"RESULT": 
{
    "COLUMNS": ["ID","name","ENABLED","perms","vcenabled","vcvalue","checkenabled","checkvalue","indxenabled","indxvalue"],
    "DATA": [
                [7,"Site-A", 1, "1,2", 1, 1, 1, 0, 0, 0],
                [15,"Site-B", 1, "1,2,3,4", 1, 1, 1, 0, 0, 0]
    ]
},
"ERROR": 0
},

formatted = [];

_.each(plain.RESULT.DATA, function(value) {
    var tmp = {};
     tmp = _.object(plain.RESULT.COLUMNS,value)
    formatted.push(tmp);
});

 console.log(formatted);

Answer 4

Try this using underscorejs.

var plain = {
    "RESULT": 
    {
        "COLUMNS": ["ID","name","ENABLED","perms","vcenabled","vcvalue","checkenabled","checkvalue","indxenabled","indxvalue"],
        "DATA": [
                [7,"Site-A", 1, "1,2", 1, 1, 1, 0, 0, 0],
                [15,"Site-B", 1, "1,2,3,4", 1, 1, 1, 0, 0, 0]
        ]
    },
    "ERROR": 0
}
   , formatted = [];

_.each(plain.RESULT.DATA, function(value) {
    var tmp = {};
    _.each(value, function(parameter, pos) {
        tmp[plain.RESULT.COLUMNS[pos]] = parameter;
    });
    formatted.push(tmp);
});

console.log(formatted);

http://jsfiddle.net/kxR88/

Answer 5

Actually, you could use a combination of Array#map for the array and Array#reduce for the objects with the new properties

var data = { RESULT: { COLUMNS: ["ID", "name", "ENABLED", "perms", "vcenabled", "vcvalue", "checkenabled", "checkvalue", "indxenabled", "indxvalue"], DATA: [[7, "Site-A", 1, "1,2", 1, 1, 1, 0, 0, 0], [15, "Site-B", 1, "1,2,3,4", 1, 1, 1, 0, 0, 0]] }, ERROR: 0 },
    result = data.RESULT.DATA.map(function (a) {
        return a.reduce(function (o, d, i) {
            o[data.RESULT.COLUMNS[i]] = d;
            return o;
        }, {});
    });

console.log(result);

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With ES6, you could use Object.assign with spread syntax ....

Object.assign adds properties to the given object and returns this object.

Spread syntax ... takes an array and insert the elements as parameters to the function.

var data = { RESULT: { COLUMNS: ["ID", "name", "ENABLED", "perms", "vcenabled", "vcvalue", "checkenabled", "checkvalue", "indxenabled", "indxvalue"], DATA: [[7, "Site-A", 1, "1,2", 1, 1, 1, 0, 0, 0], [15, "Site-B", 1, "1,2,3,4", 1, 1, 1, 0, 0, 0]] }, ERROR: 0 },
    result = data.RESULT.DATA.map(a =>
        Object.assign(...data.RESULT.COLUMNS.map((k, i) => ({ [k]: a[i] }))));

console.log(result);

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