選擇從對象給出的屬性值代入陣列

Question

我有一個對象：

person = { 
    birth_year: 1970, 
    first_name: "John", 
    last_name: "Doe", 
    occupation: "Doctor", 
    city: "Boston", 
    married: true 
} 

我有鑰匙的名字在給定的順序數組：

keys = ["occupation", "last_name", "city"] 

我想這個數組：

["Doctor", "Doe", "Boston"] 

重要的是，答案應該保證順序（JavaScript不保證對象迭代的順序）。

我認爲在lodash /下劃線中可能有一些實用功能可以簡單地實現，但無法找出任何問題。

Answer 1

您可以使用Array.prototype.map。通過數組映射循環，並通過對每個項目應用函數來創建一個新數組。當您使用keys數組作爲起點，並返回該鍵的o的值時，您將獲得一個僅包含值的新數組。

使用「動態」鍵名稱時，可以使用object[stringKeyName]表示法檢索值。

var o = { 
 
    birth_year: 1970, 
 
    first_name: "John", 
 
    last_name: "Doe", 
 
    occupation: "Doctor", 
 
    city: "Boston", 
 
    married: true 
 
}; 
 

 
var keys = ["occupation", "last_name", "city"]; 
 

 
var result = keys.map(function(k) { return o[k]; }); 
 

 
console.log(result);

如果它適合你的風格，你可以創建一個輔助方法來代替匿名函數：

var o = { birth_year: 1970, first_name: "John", last_name: "Doe", occupation: "Doctor", city: "Boston", married: true }; 
 
var keys = ["occupation", "last_name", "city"]; 
 

 
var prop = obj => key => obj[key]; 
 
var result = keys.map(prop(o)); 
 

 
console.log(result);

Answer 2

隨着Lodash你可以使用pick和values

var o = { 
 
    birth_year: 1970, 
 
    first_name: "John", 
 
    last_name: "Doe", 
 
    occupation: "Doctor", 
 
    city: "Boston", 
 
    married: true 
 
} 
 
var keys = ["occupation", "last_name", "city"]; 
 

 
var result = _.values(_.pick(o, keys)); 
 
console.log(result)

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