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
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);
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 };
使用对象解构和展开运算符的变体:
const old_obj = {
k1: `111`,
k2: `222`,
k3: `333`
};
// destructuring, with renaming. The variable 'rest' will hold those values not assigned to kA, kB, or kC.
const {
k1: kA,
k2: kB,
k3: kC,
...rest
} = old_obj;
// now create a new object, with the renamed properties kA, kB, kC;
// spread the remaining original properties in the 'rest' variable
const newObj = {kA, kB, kC, ...rest};
对于一个键,这可以很简单:
const { k1: kA, ...rest } = old_obj;
const new_obj = { kA, ...rest }
你也可能喜欢更“传统”的风格:
const { k1, ...rest } = old_obj
const new_obj = { kA: k1, ...rest}
本页列出的一些解决方案有一些副作用:
影响键在对象中的位置,将其添加到底部(如果这对你来说很重要) 不能在IE9+中工作(如果这对你来说很重要的话)
下面是一个解决方案,它保持键的位置在相同的地方,并在IE9+兼容,但必须创建一个新的对象,可能不是最快的解决方案:
function renameObjectKey(oldObj, oldName, newName) {
const newObj = {};
Object.keys(oldObj).forEach(key => {
const value = oldObj[key];
if (key === oldName) {
newObj[newName] = value;
} else {
newObj[key] = value;
}
});
return newObj;
}
请注意:IE9在严格模式下可能不支持forEach
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
}, {})
}
我只想用ES6(ES2015)的方式!
我们需要跟上时代!
const old_obj = { k1: `111`, k2: `222`, k3: `333` }; console.log(`old_obj =\n`, old_obj); // {k1: "111", k2: "222", k3: "333"} /** * @author xgqfrms * @description ES6 ...spread & Destructuring Assignment */ const { k1: kA, k2: kB, k3: kC, } = {...old_obj} console.log(`kA = ${kA},`, `kB = ${kB},`, `kC = ${kC}\n`); // kA = 111, kB = 222, kC = 333 const new_obj = Object.assign( {}, { kA, kB, kC } ); console.log(`new_obj =\n`, new_obj); // {kA: "111", kB: "222", kC: "333"}