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

您可以尝试lodash _mapkeys。

Var用户= { 名称:“安德鲁”, id: 25日 报道:假 }; Var重命名= _。mapKeys(用户,函数(值,键){ 返回键+ "_" + user.id; }); console.log(重命名); < script src = " https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.11/lodash.js " > < /脚本>

其他回答

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;
        }
    }
);

这里的大多数答案都无法维持JS对象键值对的顺序。例如,如果您在屏幕上有一种希望修改的对象键-值对形式,那么保持对象条目的顺序就很重要。

ES6循环JS对象并将键值对替换为具有修改过的键名的新键值对的方法如下:

let newWordsObject = {};

Object.keys(oldObject).forEach(key => {
  if (key === oldKey) {
    let newPair = { [newKey]: oldObject[oldKey] };
    newWordsObject = { ...newWordsObject, ...newPair }
  } else {
    newWordsObject = { ...newWordsObject, [key]: oldObject[key] }
  }
});

该解决方案通过在旧条目的位置上添加新条目来保留条目的顺序。

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。

简单地这么做会有什么问题吗?

someObject = {...someObject, [newKey]: someObject.oldKey}
delete someObject.oldKey

如果愿意,可以将其包装在函数中:

const renameObjectKey = (object, oldKey, newKey) => {
    // if keys are the same, do nothing
    if (oldKey === newKey) return;
    // if old key doesn't exist, do nothing (alternatively, throw an error)
    if (!object.oldKey) return;
    // if new key already exists on object, do nothing (again - alternatively, throw an error)
    if (object.newKey !== undefined) return;

    object = { ...object, [newKey]: object[oldKey] };
    delete object[oldKey];

    return { ...object };
};

// in use
let myObject = {
    keyOne: 'abc',
    keyTwo: 123
};

// avoids mutating original
let renamed = renameObjectKey(myObject, 'keyTwo', 'renamedKey');

console.log(myObject, renamed);
// myObject
/* {
    "keyOne": "abc",
    "keyTwo": 123,
} */

// renamed
/* {
    "keyOne": "abc",
    "renamedKey": 123,
} */

为每个键添加前缀:

const obj = {foo: 'bar'}

const altObj = Object.fromEntries(
  Object.entries(obj).map(([key, value]) => 
    // Modify key here
    [`x-${key}`, value]
  )
)

// altObj = {'x-foo': 'bar'}