javascript - 返回对象及其属性的子集

Question

我有一个像这样的平面 JavaScript 对象:

{ 
  id: 3726492,
  kind: 'user',
  permalink: 'nicholas',
  username: 'Nicholas',
  ...
  a lot more attributes
}

我想创建一个新对象，它只具有原始对象的一部分属性。

有点像

var newObject = oldObject.fields(['id', 'username']);

newObject 会是

{ 
  id: 3726492,
  username: 'Nicholas'
}

已经有这样的东西了吗？

Answer 1

试试这个

function pick(data, keys) {
  var result = {};
  
  keys.forEach(function (key) {
    if (data.hasOwnProperty(key)) {
      result[key] = data[key];
    }
  });
  
  return result;
}

var data = { 
  id: 3726492,
  kind: 'user',
  permalink: 'nicholas',
  username: 'Nicholas'
}

var newData = pick(data, ['id', 'kind']);
console.log(newData);

underscorejs 或 lodash 中有方法 .pick

var data = { 
  id: 3726492,
  kind: 'user',
  permalink: 'nicholas',
  username: 'Nicholas',
};

var newObject = _.pick(data, 'id', 'username');
console.log(newObject);

<script src="https://cdnjs.cloudflare.com/ajax/libs/underscore.js/1.8.3/underscore.js"></script>