Merge Array to Object Array JavaScript

Question

I have an array here:

var array = [
    [
        [\'firstName\', \'Nork\'], [\'lastName\', \'James\'], [\'age\', 22], [\'position\', \'writer\']
    ],
    [
           


        

Answer 1

See this one:

var array = [
    [
        ['firstName', 'Nork'], ['lastName', 'James'], ['age', 22], ['position', 'writer']
    ],
    [
        ['firstName', 'James'], ['lastName', 'Rodel'], ['age', 25], ['position', 'programmer']
    ]
];

function changeData(array)
{
    var i,j;
    var ret = [];
    var tmp = {};

    // rotate through every line and create a temporary object which we push to the return array
    for (i=0;i<array.length;i++)
    {
        tmp = {};
        for (j=0;j<array[i].length;j++) tmp[ array[i][j][0] ] = array[i][j][1];
        ret.push(tmp);
    }
    return ret;
}

console.log(changeData(array));

Answer 2

You can simply do it using Array.prototype.map() to loop over the first array along with a Array.prototype.forEach() in its callback to loop over the sub arrays and merge them in a unique object:

var merged = array.map(function(arr) {
  var obj = {};
  arr.forEach(function(item) {
    obj[item[0]] = item[1];
  });
  return obj;
});

Demo:

var array = [
  [
    ['firstName', 'Nork'],
    ['lastName', 'James'],
    ['age', 22],
    ['position', 'writer']
  ],
  [
    ['firstName', 'James'],
    ['lastName', 'Rodel'],
    ['age', 25],
    ['position', 'programmer']
  ]
];

var merged = array.map(function(arr) {
  var obj = {};
  arr.forEach(function(item) {
    obj[item[0]] = item[1];
  });
  return obj;
});
console.log(merged);

Answer 3

Use [].map over [].reduce

---

The map() method creates a new array with the results of calling a provided function on every element in this array.

---

The reduce() method applies a function against an accumulator and each element in the array (from left to right) to reduce it to a single value.

var array = [
  [
    ['firstName', 'Nork'],
    ['lastName', 'James'],
    ['age', 22],
    ['position', 'writer']
  ],
  [
    ['firstName', 'James'],
    ['lastName', 'Rodel'],
    ['age', 25],
    ['position', 'programmer']
  ]
];

function mergeObjectArray(array) {
  return array.map(function(el) {
    return el.reduce(function(a, b) {
      a[b[0]] = b[1];
      return a;
    }, {})
  });
}
console.log(mergeObjectArray(array));

Answer 4

You have not specified how you want to merge the users. this will take your array of user objects and reduce all the results into a single object with an array of all values supplied.

var array = [
  {firstName: 'Nork', lastName: 'James', age: 22, position: 'writer'},
  {firstName: 'James', lastName: 'Rodel', age: 25, role: 'programmer'}
]

function changeData(array) {
  return array.reduce((users, user) => {
    Object.keys(user).forEach(key => {
      users[key+'s'] = Array.isArray(users[key+'s']) ? users[key+'s'].concat(user[key]) : [user[key]]
    })
    return users
  }, {})
}

console.log(
  changeData(array)
)

Answer 5

You can map into your array and assign dynamic properties like this obj[prop] = value

var array = [
    [
        ['firstName', 'Nork'], ['lastName', 'James'], ['age', 22], ['position', 'writer']
    ],
    [
        ['firstName', 'James'], ['lastName', 'Rodel'], ['age', 25], ['position', 'programmer']
    ]
];

var convertedArray = array.map(function(line){
   var obj = {};
   line.forEach(function(prop){
     obj[prop[0]]=prop[1];
   });
   return obj;
});

console.log(convertedArray);