Underscore.js - get unique property values

Question

I only recently discovered the power of underscore.js, still new to the methods I kindly ask for a suggestion:

How do I get from this:

[
    [{
        "name": "Type 2",
        "id": 14
    }],
    [{
        "name": "Type 1",
        "id": 13
    }, {
        "name": "Type 3",
        "id": 15
    }],
    [{
        "name": "Type 2",
        "id": 14
    }],
    [{
        "name": "Type 1",
        "id": 13
    }]
]

to this:

["Type 1","Type 2","Type 3"]

ie no duplicated and "name" property only.

Any suggestions much appreciated.

Answer 1

_(data).chain().flatten().pluck('name').unique().value()

（将嵌套列表转换为平面列表，从列表中的每个对象中选择name ，并使其唯一。）

Answer 2

• Use flatten first, to convert the nested array to a flat array.
• Then pluck to get the "name" values as an array
• Finally uniq

---

_.uniq(_.pluck(_.flatten(items), "name"))

Fiddle

Answer 3

var arr = _.uniq(_.map(_.flatten(array), function(e) {
    return e.name;
}));

Answer 4

_.uniq(_.pluck(x,'name'));

上面的代码足以提取不同的“名称”属性

Answer 5

Simple way:

1. use _.map to get all the names

var names = _.map(items, function(item) { return item.name});

2. Get the _.uniq from that names

var uniqueNames = _.uniq(names);