Node.js + ObjectArray + Comparison

Question

Is it possible to compare 2 object arrays in javascript. My requirement is i have to compare 2 object arrays and i have to take the common objects between those 2 object arrays:

Consider 1st object array:

[ { id_0: 356,
    name_0: 'xxxxx',
    id_1: 33,
    name_1: 'yyyyyy',
    id_2: 602,
    name_2: 'zzzzzzz',
    collecteddate: '31/03/2011',
    key: 'kkkkkkk',
    value: '0.41' },
  { id_0: 356,
    name_0: 'xxxxxx',
    id_1: 33,
    name_1: 'yyyyyy',
    id_2: 602,
    name_2: 'zzzzzz',
    collecteddate: '31/03/2011',
    key: 'k1k1k1k1k1',
    value: '0.20' },
  { id_0: 356,
    name_0: 'xxxxx',
    id_1: 33,
    name_1: 'yyyyy',
    id_2: 602,
    name_2: 'zzzzzz',
    collecteddate: '31/03/2011',
    key: 'k2k2k2k2k2k2k2',
    value: '1.30' }}]

My 2nd object array:

[ { id_0: 356,
        name_0: 'xxxxx',
        id_1: 33,
        name_1: 'yyyyyy',
        id_2: 602,
        name_2: 'zzzzzzz',
        collecteddate: '31/03/2011',
        key: 'kkkkkkk',
        value: '0.41' },
      { id_0: 356,
        name_0: 'xxxxxx',
        id_1: 33,
        name_1: 'yyyyyy',
        id_2: 602,
        name_2: 'zzzzzz',
        collecteddate: '31/03/2011',
        key: 'k1k1k1k1k1',
        value: '0.20' },
      { id_0: 356,
        name_0: 'xxxxx',
        id_1: 33,
        name_1: 'yyyyy',
        id_2: 602,
        name_2: 'zzzzzz',
        collecteddate: '31/03/2011',
        key: 'k2k2k2k2k2k2k2',
        value: '1.30' }}]

I have to compare the above 2 objects and i have to build another object with common entries of the above 2. In the above example every entry is same in 2 arrays so the third array should contain 3 entries. Is it possible to do this..Help me to solve this..Thanks in advance....

EDIT:

I have used _(underscore) library to check whether 2 objects are equal if equal i pushed that object into new array..Whether its good solution or not..

Answer 1

Solution without third library - pure javascript

Something like this (recursive) - could be optimized but less readable.

var compareAndMerge = function(object1, object2) {

 var outputObject = {};

 var compareSubObject = function(object1, object2) {
    var outputObject = {};

    for (var k in object1) {
        for (var k2 in object2) {
            if (typeof object1[k] === 'object' && typeof object2[k2] === 'object') {
                var sameObject = compareSubObject(object1[k], object2[2]);
                if (sameObject === false) {
                    return false;
                }
                outputObject[k] = object1[k];
            } else if (object1[k] === object2[k]) {
                outputObject[k] = object1[k];
            } else {
                return false;
            }
        }
    }
    return outputObject;
 };

 for (var k in object1) {
    for (var k2 in object2) {
        if (typeof object1[k] !== 'object' && object1[k] === object2[k]) {
            outputObject[k] = object1[k];
        } else if (typeof object1[k] === 'object') {
            var sameObject = compareSubObject(object1[k], object2[k]);
            if (sameObject !== false) {
                outputObject[k] = sameObject;
            }
        }
    }
 }

 return outputObject;
};

View jsfiddle example here

Answer 2

Note: This solutions assumes that all the values of the objects will be either strings or numbers.

function getCommonObjects(array1, array2) {
    var result = [];
    for (var i = 0; i < array1.length; i += 1) {
        for (var j = 0; j < array2.length; j += 1) {
            if (Object.keys(array1[i]).length === Object.keys(array2[j]).length){
                var flag = true;
                for (var key in array1[i]) {
                    if (array1[i][key] !== array2[j][key]) {
                        flag = false;
                        break;
                    }
                }
                if (flag) {
                    result.push(array2[j]);
                    break;
                }
            }
        }
    }
    return result;
}