javascript - 如何使用 lodash 循环遍历对象数组并检查该对象中的值是否与另一个数组中的项目匹配

Question

我有一系列具有如下特色组件的项目:

var featuredIds = ['footerB', 'headerA', 'landingA'];

我还有一个看起来像这样的对象数组:

[{
    "title": "first footer",
    "section": "structure",
    "categoryId": "footer",
    "uId": "footerA"
  },{
    "title": "second footer",
    "section": "structure",
    "categoryId": "footer",
    "uId": "footerB"
  },
  {
    "title": "first header",
    "section": "structure",
    "categoryId": "header",
    "uId": "headerA"
  },
  {
    "title": "first header",
    "section": "structure",
    "categoryId": "header",
    "uId": "headerB"
  },
  {
    "title": "first landing",
    "section": "structure",
    "categoryId": "landing",
    "uId": "landingA"
  },
  {
    "title": "second landing",
    "section": "structure",
    "categoryId": "landing",
    "uId": "landingB"
  },
  {
    "title": "third landing",
    "section": "structure",
    "categoryId": "landing",
    "uId": "landingC"
  },
  {
    "title": "first nav",
    "section": "structure",
    "categoryId": "navigation",
    "uId": "navA"
  },{
    "title": "first footer",
    "section": "components",
    "categoryId": "blog",
      "uId": "blogA"
  },
  {
    "title": "second footer",
    "section": "components",
    "categoryId": "blog",
    "uId": "blogB"
  },
  {
    "title": "first header",
    "section": "components",
    "categoryId": "contact_button",
    "uId": "contact_buttonA"
  },
  {
    "title": "first landing",
    "section": "components",
    "categoryId": "content_bloc",
    "uId": "content_blocA"
  },
  {
    "title": "second landing",
    "section": "components",
    "categoryId": "content_bloc",
    "uId": "content_blocB"
  },
  {
    "title": "third landing",
    "section": "components",
    "categoryId": "content_bloc",
    "uId": "content_blocC"
  },
  {
    "title": "first nav",
    "section": "components",
    "categoryId": "cover",
    "uId": "coverA"
  }]

我想创建一个新数组，它只保存与我在 featureIds 数组中提供的 featureId 相匹配的组件，如下所示:

[{
    "title": "second footer",
    "section": "structure",
    "categoryId": "footer",
    "uId": "footerB"
  },{
    "title": "first header",
    "section": "structure",
    "categoryId": "header",
    "uId": "headerA"
  },
  {
    "title": "first landing",
    "section": "structure",
    "categoryId": "landing",
    "uId": "landingA"
  }]

我已经考虑过使用 _.some、_.find 和其他一些方法，但无法得到我正在寻找的结果。我已经使用双 for 循环编写了此内容，这就是为什么我希望我们 lodash 删除它/学习新的东西。

Answer 1

您可以将 lodash 的链与 _.keyBy() 和 _.at() 一起使用:

function filterBy(arr, filters) {
  return _(features)
  .keyBy('uId')
  .at(filters)
  .value();
}

var features = [{
  "title": "first footer",
  "section": "structure",
  "categoryId": "footer",
  "uId": "footerA"
}, {
  "title": "second footer",
  "section": "structure",
  "categoryId": "footer",
  "uId": "footerB"
}, {
  "title": "first header",
  "section": "structure",
  "categoryId": "header",
  "uId": "headerA"
}, {
  "title": "first header",
  "section": "structure",
  "categoryId": "header",
  "uId": "headerB"
}, {
  "title": "first landing",
  "section": "structure",
  "categoryId": "landing",
  "uId": "landingA"
}, {
  "title": "second landing",
  "section": "structure",
  "categoryId": "landing",
  "uId": "landingB"
}, {
  "title": "third landing",
  "section": "structure",
  "categoryId": "landing",
  "uId": "landingC"
}, {
  "title": "first nav",
  "section": "structure",
  "categoryId": "navigation",
  "uId": "navA"
}, {
  "title": "first footer",
  "section": "components",
  "categoryId": "blog",
  "uId": "blogA"
}, {
  "title": "second footer",
  "section": "components",
  "categoryId": "blog",
  "uId": "blogB"
}, {
  "title": "first header",
  "section": "components",
  "categoryId": "contact_button",
  "uId": "contact_buttonA"
}, {
  "title": "first landing",
  "section": "components",
  "categoryId": "content_bloc",
  "uId": "content_blocA"
}, {
  "title": "second landing",
  "section": "components",
  "categoryId": "content_bloc",
  "uId": "content_blocB"
}, {
  "title": "third landing",
  "section": "components",
  "categoryId": "content_bloc",
  "uId": "content_blocC"
}, {
  "title": "first nav",
  "section": "components",
  "categoryId": "cover",
  "uId": "coverA"
}];

var featuredIds = ['footerB', 'headerA', 'landingA'];

var result = filterBy(features, featuredIds);

console.log(result);

<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.16.6/lodash.min.js"></script>

或者，如果您可以使用 ES6，则可以使用 Array.prototype.filter() 和 Set 的组合:

const filterBy = (arr, filters) => {
  const filtersSet = new Set(filters);
  
  return arr.filter((item) => filtersSet.has(item.uId));
};

const featuredIds = ['footerB', 'headerA', 'landingA'];

const features = [{
  "title": "first footer",
  "section": "structure",
  "categoryId": "footer",
  "uId": "footerA"
}, {
  "title": "second footer",
  "section": "structure",
  "categoryId": "footer",
  "uId": "footerB"
}, {
  "title": "first header",
  "section": "structure",
  "categoryId": "header",
  "uId": "headerA"
}, {
  "title": "first header",
  "section": "structure",
  "categoryId": "header",
  "uId": "headerB"
}, {
  "title": "first landing",
  "section": "structure",
  "categoryId": "landing",
  "uId": "landingA"
}, {
  "title": "second landing",
  "section": "structure",
  "categoryId": "landing",
  "uId": "landingB"
}, {
  "title": "third landing",
  "section": "structure",
  "categoryId": "landing",
  "uId": "landingC"
}, {
  "title": "first nav",
  "section": "structure",
  "categoryId": "navigation",
  "uId": "navA"
}, {
  "title": "first footer",
  "section": "components",
  "categoryId": "blog",
  "uId": "blogA"
}, {
  "title": "second footer",
  "section": "components",
  "categoryId": "blog",
  "uId": "blogB"
}, {
  "title": "first header",
  "section": "components",
  "categoryId": "contact_button",
  "uId": "contact_buttonA"
}, {
  "title": "first landing",
  "section": "components",
  "categoryId": "content_bloc",
  "uId": "content_blocA"
}, {
  "title": "second landing",
  "section": "components",
  "categoryId": "content_bloc",
  "uId": "content_blocB"
}, {
  "title": "third landing",
  "section": "components",
  "categoryId": "content_bloc",
  "uId": "content_blocC"
}, {
  "title": "first nav",
  "section": "components",
  "categoryId": "cover",
  "uId": "coverA"
}];

const result = filterBy(features, featuredIds);

console.log(result);

另一个 lodash 选项是 _.intersectionWith():

function filterBy(arr, filters) {
  return _.intersectionWith(arr, filters, function(value, filter) {
    return value.uId === filter;
  });
}

var features = [{
  "title": "first footer",
  "section": "structure",
  "categoryId": "footer",
  "uId": "footerA"
}, {
  "title": "second footer",
  "section": "structure",
  "categoryId": "footer",
  "uId": "footerB"
}, {
  "title": "first header",
  "section": "structure",
  "categoryId": "header",
  "uId": "headerA"
}, {
  "title": "first header",
  "section": "structure",
  "categoryId": "header",
  "uId": "headerB"
}, {
  "title": "first landing",
  "section": "structure",
  "categoryId": "landing",
  "uId": "landingA"
}, {
  "title": "second landing",
  "section": "structure",
  "categoryId": "landing",
  "uId": "landingB"
}, {
  "title": "third landing",
  "section": "structure",
  "categoryId": "landing",
  "uId": "landingC"
}, {
  "title": "first nav",
  "section": "structure",
  "categoryId": "navigation",
  "uId": "navA"
}, {
  "title": "first footer",
  "section": "components",
  "categoryId": "blog",
  "uId": "blogA"
}, {
  "title": "second footer",
  "section": "components",
  "categoryId": "blog",
  "uId": "blogB"
}, {
  "title": "first header",
  "section": "components",
  "categoryId": "contact_button",
  "uId": "contact_buttonA"
}, {
  "title": "first landing",
  "section": "components",
  "categoryId": "content_bloc",
  "uId": "content_blocA"
}, {
  "title": "second landing",
  "section": "components",
  "categoryId": "content_bloc",
  "uId": "content_blocB"
}, {
  "title": "third landing",
  "section": "components",
  "categoryId": "content_bloc",
  "uId": "content_blocC"
}, {
  "title": "first nav",
  "section": "components",
  "categoryId": "cover",
  "uId": "coverA"
}];

var featuredIds = ['footerB', 'headerA', 'landingA'];

var result = filterBy(features, featuredIds);

console.log(result);

<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.16.6/lodash.min.js"></script>