js 改变对象的key

//oldMap要改变的对象，newKey改变的key
let newMap = this.replaceMapKey({quantity:'20',amout:'200'},newQuantity,newAmount)
replaceMapKey(oldMap, newKey, newKey1) {
    var keyMap = {quantity: newKey, amount: newKey1};
    var objs = Object.keys(oldMap).reduce((newData, key) => {
        let newKey = keyMap[key] || key
        newData[newKey] = oldMap[key]
        return newData
    }, {});
    return objs;
},
console.log(newMap)
输出结果为：
{newQuantity:'20',newAmount:'200'}