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 ];
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
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,
} */
其他回答
const clone = (obj) => Object.assign({}, obj);
const renameKey = (object, key, newKey) => {
const clonedObj = clone(object);
const targetKey = clonedObj[key];
delete clonedObj[key];
clonedObj[newKey] = targetKey;
return clonedObj;
};
let contact = {radiant: 11, dire: 22};
contact = renameKey(contact, 'radiant', 'aplha');
contact = renameKey(contact, 'dire', 'omega');
console.log(contact); // { aplha: 11, omega: 22 };
在我看来,你的方法是最优化的。但你最终会得到重新排序的密钥。新创建的密钥将附加在末尾。我知道你不应该依赖键的顺序,但如果你需要保存它,你将需要遍历所有键并一个接一个地构造新对象,在这个过程中替换有问题的键。
是这样的:
var new_o={};
for (var i in o)
{
if (i==old_key) new_o[new_key]=o[old_key];
else new_o[i]=o[i];
}
o=new_o;
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,
} */
下面是创建具有重命名键的新对象的示例。
let x = { id: "checkout", name: "git checkout", description: "checkout repository" };
let renamed = Object.entries(x).reduce((u, [n, v]) => {
u[`__${n}`] = v;
return u;
}, {});
重命名对象键的另一种方法:
让我们考虑这个对象:
let obj = {"name": "John", "id": 1, "last_name": "Doe"}
让我们重命名name key为first_name:
let { name: first_name, ...rest } = obj;
obj = { first_name, ...rest }
现在对象是:
{"first_name": "John", "id": 1, "last_name": "Doe"}