Create object from three arrays

Question

A little bit stuck on the following scenario. I have three arrays, and using the arrays would like to create a new object.

var fields = ['firstName', 'lastName', 'email'],
oldVals = ['John', 'Doe', '[email protected]'],
newVals = ['Jo','Do','[email protected]'];

The new object should be as :

{
 "firstName": {
    "oldValue": "John",
    "newValue": "Jo"
 },
 "lastName": {
    "oldValue": "John",
    "newValue": "Do"
 },
 "email": {
    "oldValue": "[email protected]",
    "newValue": "[email protected]"
 }
}

Thanks in advance.

Are you asking for a function that would convert these arrays into an object? — juil
– juil, Commented May 23, 2016 at 16:54
What part of this are you stuck on? What have you done so far to solve this? — gen_Eric
– gen_Eric, Commented May 23, 2016 at 16:54
What is the source of this array ? Depending on the indexes looks ugly to me... — Rayon
– Rayon, Commented May 23, 2016 at 16:56

Paarth · Accepted Answer · 2016-05-23 16:57:20Z

6

// first check that your arrays are actually all the same length. Then...

var obj = {};
for(var i=0;i<fields.length;i++) {
    obj[fields[i]] = {
        oldValue: oldVals[i],
        newValue: newVals[i]
    }
}

answered May 23, 2016 at 16:57

Paarth

10.5k4 gold badges30 silver badges37 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Jagdish Idhate · Accepted Answer · 2016-05-23 17:04:39Z

3

Assuming lengths are same, Using reduce function of array

fields.reduce(function(res,x,index){
  res[x] = { 
   oldValue:oldVals[index],
   newValue:newVals[index]
   }
  return res;
},{});

answered May 23, 2016 at 17:04

Jagdish Idhate

7,7529 gold badges37 silver badges58 bronze badges

Comments

Nina Scholz · Accepted Answer · 2016-05-23 17:11:28Z

1

A proposal with Array#forEach and some arrays for dynamic generation of the object.

var fields = ['firstName', 'lastName', 'email'],
    oldVals = ['John', 'Doe', '[email protected]'],
    newVals = ['Jo', 'Do', '[email protected]'],
    object = function (array, keys1, keys2) {
        var r = {};
        keys1.forEach(function (k1, i) {
            r[k1] = r[k1] || {};
            keys2.forEach(function (k2, j) {
                r[k1][k2] = array[j][i];
            });
        });
        return r;
    }([oldVals, newVals], fields, ['oldVals', 'newVals']);

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

answered May 23, 2016 at 17:11

Nina Scholz

388k26 gold badges367 silver badges417 bronze badges

Comments

Anil Kumar · Accepted Answer · 2016-05-23 17:00:58Z

0

A property can be created dynamically thus:

objectName[propertyVariable] = valueVariable;

So in the present case something like this would do the trick.

var object1 = {};
object1[fields[0]] = { oldValue: oldVals[0], newValue: newVals[0] }

answered May 23, 2016 at 17:00

Anil Kumar

1246 bronze badges

Comments

Bassam Rubaye · Accepted Answer · 2016-05-23 17:34:42Z

0

I wanted to add this solution , which will encapsulate it in a method, like this :

var fields = ['firstName', 'lastName', 'email'],
oldVals = ['John', 'Doe', '[email protected]'],
newVals = ['Jo','Do','[email protected]'];


function createCustomObj(fields , oldVals, newVals){
var obj={};

    fields.forEach( function(f, i){
        obj[f]={};
    obj[f]['oldValue']= oldVals[i];
    obj[f]['newValue']= newVals[i];
});

return obj;

};

console.log(createCustomObj(fields, oldVals, newVals));

https://jsfiddle.net/x54b0rhk/

answered May 23, 2016 at 17:34

Bassam Rubaye

3021 silver badge4 bronze badges

Collectives™ on Stack Overflow

Create object from three arrays

5 Answers 5

Comments

Comments

Comments

Comments

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

5 Answers 5

Comments

Comments

Comments

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related