匹配两个对象键并以角度 4 显示另一个对象键值答案

【问题标题】：Match two object keys and display another object key value in angular 4匹配两个对象键并以角度 4 显示另一个对象键值
【发布时间】：2018-09-06 17:52:11
【问题描述】：

我有两个这样的对象

languages = [
  {
    "name": "english",
    "iso_639_2_code": "eng"
  },
  {
    "name": "esperanto",
    "iso_639_2_code": "epo"
  },
  {
    "name": "estonian",
    "iso_639_2_code": "est"
  }
]

另一个是

user = [
    { 
    name: "john",
    language: "eng",
    country: "US"
   }   
];

我要做的是，将 iso_639_2_code 与用户的语言相匹配，然后我必须显示语言名称而不是语言中的代码。基本上两者都是不同的api，我不知道如何在angular 4中做到这一点。这是我正在尝试的链接https://stackblitz.com/edit/angular-9k2nff?file=app%2Fapp.component.ts

【问题讨论】：

标签： javascript angular javascript-objects

【解决方案1】：

使用find

var output = languages.find(s => s.iso_639_2_code == user[0].language).name;

演示

var languages = [{
    "name": "english",
    "iso_639_2_code": "eng"
  },
  {
    "name": "esperanto",
    "iso_639_2_code": "epo"
  },
  {
    "name": "estonian",
    "iso_639_2_code": "est"
  }
];
var user = [{
    name: "john",
    language: "eng",
    country: "US"
  }

];

var output = languages.find(s => s.iso_639_2_code == user[0].language).name;

console.log(output);

或者，如果有多个用户，并且您想为每个用户查找语言名称，则使用map

var output = user.map(t => 
   languages.find(s => 
      s.iso_639_2_code == t.language).name);

演示

var languages = [{
    "name": "english",
    "iso_639_2_code": "eng"
  },
  {
    "name": "esperanto",
    "iso_639_2_code": "epo"
  },
  {
    "name": "estonian",
    "iso_639_2_code": "est"
  }
];
var user = [{
    name: "john",
    language: "eng",
    country: "US"
  }

];

var output = user.map(t => 
   languages.find(s => 
      s.iso_639_2_code == t.language).name);

console.log(output);

【讨论】：

【解决方案2】：

使用数组查找：

var languages = [
    {"name": "english", "iso_639_2_code": "eng"},
    {"name": "esperanto","iso_639_2_code": "epo"},
    {"name": "estonian","iso_639_2_code": "est"}
];
var user = [{name: "john",language: "eng",country: "US"}];

var language = languages.find(l => l.iso_639_2_code === user[0].language);
var languageName = language && language.name; // <-- also prevent error when there is no corresponding language found
console.log(languageName);

编辑：

如果有多个用户，它将是：

var languages = [
    {"name": "english", "iso_639_2_code": "eng"},
    {"name": "esperanto","iso_639_2_code": "epo"},
    {"name": "estonian","iso_639_2_code": "est"}
];
var users = [
    {name: "john",language: "eng",country: "US"},
    {name: "john",language: "epo",country: "Esperanto"}
];

var languageNames = languages.filter(
    l => users.find(u => l.iso_639_2_code === u.language)
).map(lang => lang.name);

console.log(languageNames);

【讨论】：

【解决方案3】：

我认为这就是你需要的，输出只需运行 sn-p ：

var languages = [
  {
    "name": "english",
    "iso_639_2_code": "eng"
  },
  {
    "name": "esperanto",
    "iso_639_2_code": "epo"
  },
  {
    "name": "estonian",
    "iso_639_2_code": "est"
  }
];

var user = [
    { 
    name: "john",
    language: "eng",
    country: "US"
   }

];

user.map(u => {
  let flang = languages.filter(lang => lang.iso_639_2_code === u.language);
  if(flang) {
    u.language = flang[0].name;
  }
  return u;
})

console.log(user);

【讨论】：

【解决方案4】：

var languages=[
        {"name":"english","iso_639_2_code":"eng"}, 
        {"name":"esperanto","iso_639_2_code":"epo"}, 
        {"name":"estonian","iso_639_2_code":"est"}
    ];
    var user=[
        {name:"john",language:"eng",country:"US"}
    ];
    var languageFound = languages.find(lang => lang.iso_639_2_code === user[0].language);
    if(languageFound){
      var languageName = languageFound.name;
      console.log(languageName);
    }

【讨论】：