How to populate A multi-dimensional array to multi-dimension object in JavaScript?

Question

I've been trying to figure for quite a while on populating my 2D array to object. I tried using _.map() , but it did not gave me the result I was expecting.

I have an array that is stored:

// My array
var myArray = [ [foo, bar, fiz], [faz, far, fee] ];

// My object
var myObject = {
    key1: {
        val1: 1,
        val2: 2,
        val3: 3
    },
    key2: {
        val1: 1,
        val2: 2,
        val3: 3
    }
}

And the result I am trying to achieve is:

var myObject = {
    key1: {
        val1: foo,
        val2: bar,
        val3: fiz
    },
    key2: {
        val1: faz,
        val2: far,
        val3: fee
    }
}

Here what I got so far:

_.map(myObj, x => {
    for (var i = 0; myArray.length; i++) {
        x.val1 = myArray[i][0];
        x.val2 = myArray[i][1];
        x.val3 = myArray[i][2];
    }
}

The issue I encountered with _.map() I want it to iterate only one time. Since the length of array and object is the same, I don't think is necessary to iterate twice. Unfortunately my array does not have a key which I can use it to distinguish, or else I would have used Object.assign() .

Answer 1

Since the object's original values are discarded, and the keys of the object can be reproduced easily, you can build the object from the array using 2 Array#reduce methods:

 var myArray = [ ['foo', 'bar', 'fiz'], ['faz', 'far', 'fee'] ]; var myObject = myArray.reduce(function(obj, arr, i) { obj['key' + (i + 1)] = arr.reduce(function(o, item, j) { o['val' + (j + 1)] = item; return o; }, {}); return obj; }, {}); console.log(myObject); 

Answer 2

For a conversion, you need a double nested loop for each array. Then generate the key and build the object and content.

 var array = [['foo', 'bar', 'fiz'], ['faz', 'far', 'fee']], object = {}; array.forEach(function (a, i) { var key = 'key' + (1 + i); object[key] = object[key] || {}; a.forEach(function (b, j) { object[key]['val' + (1 + j)] = b; }) }); console.log(object); 

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For variable keys, you could use some arrays with the keys and take it for the outer and inner level.

 var array = [['foo', 'bar', 'fiz'], ['faz', 'far', 'fee']], topKeys = ['key1', 'key2'], subKeys = ['val1', 'val2', 'val3'], object = {}; array.forEach(function (a, i) { object[topKeys[i]] = object[topKeys[i]] || {}; a.forEach(function (b, j) { object[topKeys[i]][subKeys[j]] = b; }) }); console.log(object); 

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