How to get unique objects from objects array in javascript

Question

I have an array of objects that looks like the image below. Is there a way by which I can have an array that contains unique objects with respect to id ? We can see below that the id are same at index [0] and index [2].

Is there a way that I can get an array containing objects with unique id and the first object from the last index is added to the unique array rather than the first object. In this case, Object at index[2] should be added instead of object at index[0]:

Answer 1

To get an array of "unique" objects(with last index within the list) for your particular case use the following approach (Array.forEach, Array.map and Object.keys functions):

// exemplary array of objects (id 'WAew111' occurs twice)
var arr = [{id: 'WAew111', text: "first"}, {id: 'WAew222', text: "b"}, {id: 'WAew111', text: "last"}, {id: 'WAew33', text: "c"}],
    obj = {}, new_arr = [];

// in the end the last unique object will be considered
arr.forEach(function(v){
    obj[v['id']] = v;
});
new_arr = Object.keys(obj).map(function(id) { return obj[id]; });

console.log(JSON.stringify(new_arr, 0, 4));

The output:

[
    {
        "id": "WAew111",
        "text": "last"
    },
    {
        "id": "WAew222",
        "text": "b"
    },
    {
        "id": "WAew33",
        "text": "c"
    }
]