let person = {name: "lisi"}

for (key in person) {

    console.log(key)

}

Object.keys(person)

let person = {name: "lisi"}

for (key in person) {

    console.log(key)

}

Object.keys(person)

let objectBase = Object.getPrototypeOf(person)

let descriptor = Object.getOwnPropertyDescriptor(objectBase, "toString")

console.log(descriptor)

//output:

{

    value: [Function: toString],

    writable: true, // 是否只读

    enumerable: false, //是否可遍历

    configurable: true // 是否可删除

}

Object.defineProperty(person, 'name', {

    writable: false,

    enumerable: false,

    configurable: false

})