Turn object into array, add object as new element

Question

Trying to transform an object of objects:

var items: {
    item_a: {
        state: 'item_a status'
    },
    item_b: {
        state: 'item_b status'
    }
};

into an array of objects, whilst adding a new array element to the object (the object key):

var items = [{
    name: 'item_a',
    state: 'item_a status'
}, {
    name: 'item_b',
    state: 'item_b status'
}];

My naive attempt, which works, is thus:

var arrayOfItems = [];
for(var x in items){
    var itemObj = {
        name: x
    };
    for(var y in items[x]){
        itemObj[y] = items[x][y];
    }
    arrayOfItems.push(itemObj);
}

I'm wondering if there's a cleaner way to do this, using maybe something Underscore/LoDash?

When you are posting a question, please include all the requirements in the question. — thefourtheye
– thefourtheye, Commented May 14, 2015 at 14:48

Adam Boduch · Accepted Answer · 2015-05-14 15:05:30Z

1

I would use map() for this:

_.map(items, function(item, key) {
    return _.assign({ name: key }, item);
});
// →
// [
//   {
//     name: 'item_a',
//     state: 'item_a status'
//   },
//   {
//     name: 'item_b',
//     state: 'item_b status'
//   }
// ]

Since map() always returns an array, you're halfway there. You just need the callback to generate your array items. You can use the assign() function to setup your new name property, and then add the rest of the properties.

answered May 14, 2015 at 15:05

Adam Boduch

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Comments

Daniel Aranda · Accepted Answer · 2015-05-14 17:03:37Z

0

var newItems = _.map(items, function(item, key){
  item.name = key;
  return item;
});
console.log(newItems);

edited May 14, 2015 at 17:03

answered May 14, 2015 at 14:43

Daniel Aranda

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1 Comment

thefourtheye Over a year ago

This mutates the original object. I feel that, this beats the important idea in functional programming, not mutating objects.

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