Javascript Map和Filter在兩個數組上

Question

我有一個像這樣的數組：

arr = ['AD','CI','AI']

我有一個像

{ 
  "AD": "Mailing Address",
  "CI": "Additional Interest",
  "HO": "Homeowners",
  "AI": "Additional Interest"
}

在這里，對象包含鍵值對並形成數組鍵，該數組鍵如何將鍵與對象進行比較並獲取鍵的值。 如何從對象獲取數組鍵的值？

Answer 1

使用Array.forEach()遍歷數組並從對象獲取值：

 var arr = ['AD','CI','AI']; var obj = {"AD": "Mailing Address","CI": "Additional Interest","HO":"Homeowners","AI": "Additional Interest"}; arr.forEach(key => console.log(obj[key])); 

如果您想在循環中進一步使用該值，則將其設置為多行，例如：

 var arr = ['AD','CI','AI']; var obj = {"AD": "Mailing Address","CI": "Additional Interest","HO":"Homeowners","AI": "Additional Interest"}; arr.forEach((key) => { //some processing here console.log(obj[key]); }); 

使用map()獲取這些值的數組：

 var arr = ['AD','CI','AI']; var obj = {"AD": "Mailing Address","CI": "Additional Interest","HO":"Homeowners","AI": "Additional Interest"}; var res = arr.map((key) => obj[key]); console.log(res); 

Answer 2

這種單行代碼將為您提供包含對象值的數組result 。

let result = arr.map(a=>obj[a]);

Answer 3

你的情況需要數組嗎？ 如果只需要對象的值，則可以執行以下操作：

const obj = { 
  "AD": "Mailing Address",
  "CI": "Additional Interest",
  "HO": "Homeowners",
  "AI": "Additional Interest"
};

Object.entries(obj).forEach(([key, value]) => console.log(`${key}: ${value}`));

要么

const obj = { 
  "AD": "Mailing Address",
  "CI": "Additional Interest",
  "HO": "Homeowners",
  "AI": "Additional Interest"
};

Object.keys(obj).forEach((key) => console.log(`${obj[key]}`));

希望這會有所幫助！