Converting a JS object to an array using jQuery

Question

My application creates a JavaScript object, like the following:

myObj= {1:[Array-Data], 2:[Array-Data]}

But I need this object as an array.

Answer 1

If you want to keep the name of the object's properties as values. Example:

var fields = {
    Name: { type: 'string', maxLength: 50 },
    Age: { type: 'number', minValue: 0 }
}

Use Object.keys(), Array.map() and Object.assign():

var columns = Object.keys( fields ).map( p => Object.assign( fields[p], {field:p} ) )

Result:

[ { field: 'Name', type: 'string', maxLength: 50 }, 
  { field: 'Age', type: 'number', minValue: 0 } ]

Explanation:

Object.keys() enumerates all the properties of the source ; .map() applies the => function to each property and returns an Array ; Object.assign() merges name and value for each property.

Answer 2

Fiddle Demo

Extension to answer of bjornd .

var myObj = {
    1: [1, [2], 3],
    2: [4, 5, [6]]
}, count = 0,
    i;
//count the JavaScript object length supporting IE < 9 also
for (i in myObj) {
    if (myObj.hasOwnProperty(i)) {
        count++;
    }
}
//count = Object.keys(myObj).length;// but not support IE < 9
myObj.length = count + 1; //max index + 1
myArr = Array.prototype.slice.apply(myObj);
console.log(myArr);

---

Reference

Array.prototype.slice()

Function.prototype.apply()

Object.prototype.hasOwnProperty()

Object.keys()

Answer 3

After some tests, here is a general object to array function convertor:

You have the object:

var obj = {
    some_key_1: "some_value_1"
    some_key_2: "some_value_2"
};

The function:

function ObjectToArray(o)
{
    var k = Object.getOwnPropertyNames(o);
    var v = Object.values(o);

    var c = function(l)
    {
        this.k = [];
        this.v = [];
        this.length = l;
    };

    var r = new c(k.length);

    for (var i = 0; i < k.length; i++)
    {
        r.k[i] = k[i];
        r.v[i] = v[i];
    }

    return r;
}

Function Use:

var arr = ObjectToArray(obj);

You Get:

arr {
    key: [
        "some_key_1",
        "some_key_2"
    ],
    value: [
        "some_value_1",
        "some_value_2"
    ],
    length: 2
}

So then you can reach all keys & values like:

for (var i = 0; i < arr.length; i++)
{
    console.log(arr.key[i] + " = " + arr.value[i]);
}

Result in console:

some_key_1 = some_value_1
some_key_2 = some_value_2

Edit:

Or in prototype form:

Object.prototype.objectToArray = function()
{
    if (
        typeof this != 'object' ||
        typeof this.length != "undefined"
    ) {
        return false;
    }

    var k = Object.getOwnPropertyNames(this);
    var v = Object.values(this);

    var c = function(l)
    {
        this.k = [];
        this.v = [];
        this.length = l;
    };

    var r = new c(k.length);

    for (var i = 0; i < k.length; i++)
    {
        r.k[i] = k[i];
        r.v[i] = v[i];
    }

    return r;
};

And then use like:

console.log(obj.objectToArray);

Answer 4

Simply do

Object.values(obj);

That's all!

Answer 5

If you know the maximum index in you object you can do the following:

var myObj = {
    1: ['c', 'd'],
    2: ['a', 'b']
  },
  myArr;

myObj.length = 3; //max index + 1
myArr = Array.prototype.slice.apply(myObj);
console.log(myArr); //[undefined, ['c', 'd'], ['a', 'b']]

Answer 6

ECMASCRIPT 5:

Object.keys(myObj).map(function(x) { return myObj[x]; })

ECMASCRIPT 2015 or ES6:

Object.keys(myObj).map(x => myObj[x])