javascript - 使用过滤器过滤对象

Question

我有如下对象数组:

pages= [
   {
      "id":1,
      "name":"name1",
      "languages":[
         {
            "id":1,
            "lang":"en"
         },
         {
            "id":2,
            "lang":"de"
         }
      ]
   },
   {
      "id":2,
      "name":"name2",
      "languages":[
         {
            "id":1,
            "lang":"en"
         },
         {
            "id":2,
            "lang":"de"
         }
      ]
   },
   {
      "id":3,
      "name":"name3",
      "languages":[
         {
            "id":1,
            "lang":"en"
         }
      ]
   }
]

语言数组(这些将通过单击复选框来设置)如下所示:

selectedLanguages=['en'];

现在，我想根据 selectedLanguages 值过滤主数组。我试过以下代码:

pages.filter(page => {
    var present = false;
    page.languages.map(l => {
        if(selectedLanguages.includes(l.lang)) {
            present = true;
        }
    });
    if(present) {
        return page;
    }
})

期望的输出:如果 selectedLanguages = ['en'] 那么 pages 中的所有项目，如果 de 那么前 2 个元素。

它可以工作，但我很好奇是否可以让它变得更好？

任何建议都会有所帮助 :) 谢谢。

Answer 1

您可以使用 Array#Filter 的组合, Array#find和 Array#includes为此:

let pages= [
   {
      "id":1,
      "name":"name1",
      "languages":[
         {
            "id":1,
            "lang":"en"
         },
         {
            "id":2,
            "lang":"de"
         }
      ]
   },
   {
      "id":2,
      "name":"name2",
      "languages":[
         {
            "id":1,
            "lang":"en"
         },
         {
            "id":2,
            "lang":"fr"
         }
      ]
   }
]

let selectedLanguages=['fr'];

let result = pages.filter(e => e.languages.find(l => selectedLanguages.includes(l.lang)));
console.log(result);