[javascript] Converting a JS object to an array using jQuery

My application creates a JavaScript object, like the following:

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

But I need this object as an array.

array[1]:[Array-Data]
array[2]:[Array-Data]

So I tried to convert this object to an array by iterating with $.each through the object and adding the element to an array:

x=[]
$.each(myObj, function(i,n) {
    x.push(n);});

Is there an better way to convert an object to an array or maybe a function?

The best method would be using a javascript -only function:

var myArr = Array.prototype.slice.call(myObj, 0);

I think you can use for in but checking if the property is not inerithed

myObj= {1:[Array-Data], 2:[Array-Data]}
var arr =[];
for( var i in myObj ) {
    if (myObj.hasOwnProperty(i)){
       arr.push(myObj[i]);
    }
}

EDIT - if you want you could also keep the indexes of your object, but you have to check if they are numeric (and you get undefined values for missing indexes:

function isNumber(n) {
  return !isNaN(parseFloat(n)) && isFinite(n);
}

myObj= {1:[1,2], 2:[3,4]}
var arr =[];
for( var i in myObj ) {
    if (myObj.hasOwnProperty(i)){
        if (isNumber(i)){
            arr[i] = myObj[i];
        }else{
          arr.push(myObj[i]);
        }
    }
}

You can create a simple function to do the conversion from object to array, something like this can do the job for you using pure javascript:

var objectToArray = function(obj) {
  var arr = [];
  if ('object' !== typeof obj || 'undefined' === typeof obj || Array.isArray(obj)) {
    return obj;
  } else {
    Object.keys(obj).map(x=>arr.push(obj[x]));
  }
  return arr;
};

or this one:

var objectToArray = function(obj) {
  var arr =[];
  for(let o in obj) {
    if (obj.hasOwnProperty(o)) {
      arr.push(obj[o]);
    }
  }
  return arr;
};

and call and use the function as below:

var obj = {1:'a', 2:'b', 3:'c', 4:'d', 5:'e'};
objectToArray(obj); // return ["a", "b", "c", "d", "e"]

Also in the future we will have something called Object.values(obj), similar to Object.keys(obj) which will return all properties for you as an array, but not supported in many browsers yet...

I made a custom function:

    Object.prototype.toArray=function(){
    var arr=new Array();
    for( var i in this ) {
        if (this.hasOwnProperty(i)){
            arr.push(this[i]);
        }
    }
    return arr;
};

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

var myObj = {_x000D_
    1: ['c', 'd'],_x000D_
    2: ['a', 'b']_x000D_
  },_x000D_
  myArr;_x000D_
_x000D_
myObj.length = 3; //max index + 1_x000D_
myArr = Array.prototype.slice.apply(myObj);_x000D_
console.log(myArr); //[undefined, ['c', 'd'], ['a', 'b']]

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);

Array.prototype.slice()

Function.prototype.apply()

Object.prototype.hasOwnProperty()

Object.keys()

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);

The solving is very simple

var my_obj = {1:[Array-Data], 2:[Array-Data]}
Object.keys(my_obj).map(function(property_name){ 
    return my_obj[property_name]; 
});

Nowadays, there is a simple way to do this : Object.values().

var myObj = {
    1: [1, 2, 3],
    2: [4, 5, 6]
};

console.log(Object.values(myObj));

Output:

[[1, 2, 3], [4, 5, 6]]

This doesn't required jQuery, it's been defined in ECMAScript 2017.
It's supported by every modern browser (forget IE).

ES8 way made easy:

The official documentation

    const obj = { x: 'xxx', y: 1 };_x000D_
    let arr = Object.values(obj); // ['xxx', 1]_x000D_
    console.log(arr);

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.

How about jQuery.makeArray(obj)

This is how I did it in my app.

x = [];
for( var i in myObj ) {
    x[i] = myObj[i];
}

If you are looking for a functional approach:

var obj = {1: 11, 2: 22};
var arr = Object.keys(obj).map(function (key) { return obj[key]; });

Results in:

[11, 22]

The same with an ES6 arrow function:

Object.keys(obj).map(key => obj[key])

With ES7 you will be able to use Object.values instead (more information):

var arr = Object.values(obj);

Or if you are already using Underscore/Lo-Dash:

var arr = _.values(obj)

Simply do

Object.values(obj);

That's all!

Since ES5 Object.keys() returns an array containing the properties defined directly on an object (excluding properties defined in the prototype chain):

Object.keys(yourObject).map(function(key){ return yourObject[key] });

ES6 takes it one step further with arrow functions:

Object.keys(yourObject).map(key => yourObject[key]);

ECMASCRIPT 5:

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

ECMASCRIPT 2015 or ES6:

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