是否有一个聪明的(即优化)方法重命名一个关键在javascript对象?

一种非优化的方式是:

o[ new_key ] = o[ old_key ];
delete o[ old_key ];

当前回答

const data = res
const lista = []
let newElement: any

if (data && data.length > 0) {

  data.forEach(element => {
      newElement = element

      Object.entries(newElement).map(([key, value]) =>
        Object.assign(newElement, {
          [key.toLowerCase()]: value
        }, delete newElement[key], delete newElement['_id'])
      )
    lista.push(newElement)
  })
}
return lista

其他回答

还有一种最强大的REDUCE方法。

数据= {\ key1:“value1”,key2:“value2”,key3:“value3”}; 键文件夹= {\ key1:“firstkey”,key2:“secondkey”,key3:“thirdkey” mappedData = Object.keys . .还原((obj,k) =>对象。assign(obj, {\ [keyMap]]:数据[k]},{\}; 控制台日志(mappedData); 第一个“value1”、“secondkey”、“value2”、“thirdkey”、“value3”……

在寻找了很多答案后,这是我最好的解决方案:

const renameKey = (oldKey, newKey) => {
  _.reduce(obj, (newObj, value, key) => {
    newObj[oldKey === key ? newKey : key] = value
    return newObj
  }, {})
}

很明显,它没有替换原来的键,而是构造了一个新对象。 问题中的方法有效,但会改变对象的顺序,因为它将新的键-值添加到最后一个对象上。

我会这样做:

function renameKeys(dict, keyMap) {
  return _.reduce(dict, function(newDict, val, oldKey) {
    var newKey = keyMap[oldKey] || oldKey
    newDict[newKey] = val 
    return newDict
  }, {})
}

您可以将工作包装在一个函数中,并将其分配给Object原型。也许可以使用流畅的界面样式使多个重命名流动。

Object.prototype.renameProperty = function (oldName, newName) {
     // Do nothing if the names are the same
     if (oldName === newName) {
         return this;
     }
    // Check for the old property name to avoid a ReferenceError in strict mode.
    if (this.hasOwnProperty(oldName)) {
        this[newName] = this[oldName];
        delete this[oldName];
    }
    return this;
};

ECMAScript 5 Specific

我希望语法不是这么复杂,但它肯定是很好的有更多的控制。

Object.defineProperty(
    Object.prototype, 
    'renameProperty',
    {
        writable : false, // Cannot alter this property
        enumerable : false, // Will not show up in a for-in loop.
        configurable : false, // Cannot be deleted via the delete operator
        value : function (oldName, newName) {
            // Do nothing if the names are the same
            if (oldName === newName) {
                return this;
            }
            // Check for the old property name to 
            // avoid a ReferenceError in strict mode.
            if (this.hasOwnProperty(oldName)) {
                this[newName] = this[oldName];
                delete this[oldName];
            }
            return this;
        }
    }
);

虽然这并不是一个更好的重命名键的解决方案,但它提供了一种快速简单的ES6方法来重命名对象中的所有键,同时不改变它们所包含的数据。

let b = {a: ["1"], b:["2"]};
Object.keys(b).map(id => {
  b[`root_${id}`] = [...b[id]];
  delete b[id];
});
console.log(b);