Javascript - 根据公共值重构对象数组

Question

My input array of objects it is like this, I have an input array that looks like this :

[{"id": 657, "name": "Amadeus Basin", "contenttype": "province"}
{"id": 1173, "name": "Amazonas Basin", "contenttype": "province"}
{"id": 373, "name": "American Samoa", "contenttype": "countries"}
{"id": 1, "name": "Samoa", "contenttype": "marine"}
{"id": 796, "name": "Amhara", "contenttype": "province"}]

What I would like to achieve it would be:

[
    {
    "contenttype": "province",
    "content" : [
        {
            "id": 657,
            "name": "Amadeus Basin"
        },
        {
            "id": 1173,
            "name": "Amazonas Basin"
        },
        {
            "id": 796,
            "name": "Amhara"
        }
    ]
    }, {

        "contenttype": "countries",
        "content": [
            {
                "id": 373,
                "name" : "American Samoa"
            }
        ]

    },
    {
        "contenttype": "countries",
        "content": [
        {
            "id": 1,
            "name" : "Samoa"
        }
    ]

    }

]

splitting objects in the array according to one value and creating sub-arrays of the same objects inside these newly created objects. It would be good also using lodash.

Answer 1

You can use reduce function to iterate over each item and then check it existence in the array, if not found add new one, if found - push into it

 const data = [{"id": 657, "name": "Amadeus Basin", "contenttype": "province"}, {"id": 1173, "name": "Amazonas Basin", "contenttype": "province"}, {"id": 373, "name": "American Samoa", "contenttype": "countries"}, {"id": 1, "name": "Samoa", "contenttype": "marine"}, {"id": 796, "name": "Amhara", "contenttype": "province"}]; const grouped = data.reduce((acc, item) => { const found = acc.find(i => i.contenttype === item.contenttype); const content = {id: item.id, name: item.name}; if(found) { found.content.push(content); } else { acc.push({contenttype: item.contenttype, content: [content] }) } return acc; }, []); console.log(grouped);

Answer 2

You could use _.groupBy and map the wanted properties.

 var data = [{ id: 657, name: "Amadeus Basin", contenttype: "province" }, { id: 1173, name: "Amazonas Basin", contenttype: "province" }, { id: 373, name: "American Samoa", contenttype: "countries" }, { id: 1, name: "Samoa", contenttype: "marine" }, { id: 796, name: "Amhara", contenttype: "province" }], result = _(data) .groupBy('contenttype') .map((value, key) => ({ contenttype: key, content: _.map(value, v => _.pick(v, ['id', 'name'])) })) .value(); console.log(result);

 <script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.15.0/lodash.min.js"></script>