Comparing arrays with JavaScript or jQuery

Question

I have two arrays, one is a simple array like this:

["Adrian", "Jhon"]

And the another array is an array of objects which I converted from a jSon object. The original jSon was this:

[
    {
        "Nome": "Jhon",
        "Departamento": "Test"
    },
    {
        "Nome": "Adrian",
        "Departamento": "Test"
    },
    {
        "Nome": "Jessy",
        "Departamento": "Test"
    }
]

Now I need to compare the first array, with second one. If the Nome attribute match with my first array, I will return the entire object to another array of objects.

How can I do it with jQuery or pure JavaScript keeping the order of the first array?

EDIT - For stop taking downvotes

I already tried this:

jQuery.each(array, function (x) {
     novoRepo.push(jQuery.grep(repositorio, function (a) {
          return a.Nome == array[x];
     }));
});

But I get an exception saying that a.Nome is undefined.

Answer 1

Use the Array filter method:

var search = ["Jhon","Adrian"],
    data = [
        {"Nome": "Jhon", "Departamento": "Test"},
        {"Nome": "Adrian", "Departamento": "Test"},
        {"Nome": "Jessy", "Departamento": "Test"}
    ];
var result = data.filter(function(obj) {
    return search.indexOf(obj.Nome) >= 0;
});

For those browsers not supporting filter or indexOf (notably IE<9) you can either shim them or use the jQuery equivalents $.grep and $.inArray (see @NULL's answer below for explicit code).

---

To preserve the order of the search array and not of the data one, you can use map when for every search name there is exactly one result in the data:

result = search.map(function(name) {
    for (var i=0; i<data.length; i++)
        if (data[i].Nome == name)
            return data[i];
});

If there can be none or multiple results for each name, you better used concatMap:

result = Array.prototype.concat.apply(null, search.map(function(name) {
    return data.filter(function(obj) {
         return obj.Nome == name;
    });
});

or with $.map which does automatically unwrap arrays:

result = $.map(search, function(name) {
    return $.grep(data, function(obj) {
         return obj.Nome == name;
    });
});

Answer 2

Without a filter you can do this:

Live demo

var found = [];
$.each(["Jhon","Adrian"],function(i, name) {
  $.each(otherObject,function(j,obj) {
    if (obj.Nome==name) found.push(obj); // you could leave if only one of each
  });
});

Answer 3

To extend @Bergi's answer

Using $.grep and $.inArray would look like this:

var search = ["Jhon","Adrian"],
    data = [
        {"Nome": "Jhon", "Departamento": "Test"},
        {"Nome": "Adrian", "Departamento": "Test"},
        {"Nome": "Jessy", "Departamento": "Test"}
    ];
var result = $.grep(data, function(obj) {
    return $.inArray(obj.Nome, search) >= 0;
});