如果咱们想要确保对象被深冻结,就必须创建一个递归函数来冻结对象类型的每个属性:

没有深冻结

let person = {
name: "Leonardo",
profession: {
name: "developer"
}
};
Object.freeze(person);
person.profession.name = "doctor";
console.log(person); //output { name: 'Leonardo', profession: { name: 'doctor' } }

深冻结

function deepFreeze(object) {
let propNames = Object.getOwnPropertyNames(object);
for (let name of propNames) {
let value = object[name];
object[name] = value && typeof value === "object" ?
deepFreeze(value) : value;
}
return Object.freeze(object);
}
let person = {
name: "Leonardo",
profession: {
name: "developer"
}
};
deepFreeze(person);
person.profession.name = "doctor"; // TypeError: Cannot assign to read only property 'name' of object