使用 _.unique 在对象中返回不同值时的空数组

Question

我有一个这样的对象

data: [
  {
    "Type":"100, S4",
    "Model":"1 serie, e82",
    "Manufacturer":"BMW",
    "Vehicle":"Cars"
  },
  {
    "Type":"type 2",
    "Model":"a serie",
    "Manufacturer":"Toyota",
    "Vehicle":"Cars"
  },
  {
    "Type":"type 3",
    "Model":"v4",
    "Manufacturer":"Toyota",
    "Vehicle":"SUVs"
  }
]

然后我使用 jquery 和 lodash 库期望从对象返回不同的值。

尝试 #1：

  $.each( data, function( i, value ) {
    var vehicles = _.uniqBy(value);
    console.log(vehicles);
  });

结果：在 console.log 中打印了 3 个空数组

尝试 #2：

  $.each( data, function( i, value ) {
    var vehicles = _.uniqBy(value.Vehicle);
    console.log(vehicles);
  });

结果：分割字符内有 4 个数组

(4) ["C", "a", "r", "s"]
(4) ["C", "a", "r", "s"]
(4) ["S", "U", "V", "s"]

我希望里面有一个数组

["Cars", "SUVs"]

我该如何处理呢？感谢您的帮助！

Answer 1

您可以使用lodash#map 获取所有Vehicle 属性字符串，然后使用lodash#uniq 删除所有重复字符串。

var result = _(data).map('Vehicle').uniq().value();

var data = [
  {
    "Type":"100, S4",
    "Model":"1 serie, e82",
    "Manufacturer":"BMW",
    "Vehicle":"Cars"
  },
  {
    "Type":"type 2",
    "Model":"a serie",
    "Manufacturer":"Toyota",
    "Vehicle":"Cars"
  },
  {
    "Type":"type 3",
    "Model":"v4",
    "Manufacturer":"Toyota",
    "Vehicle":"SUVs"
  }
];

var result = _(data).map('Vehicle').uniq().value();

console.log(result);

body > div { top: 0; }

<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.4/lodash.js"></script>

Answer 2

试试这个

var vehicles  = _.uniqBy(data, function (e) {
      return e.Vehicle;
    }).map(function(veh){
    return veh.Vehicle;
});   
console.log(vehicles);