Object.assign查询
let user = { name: "Nasir", age: 25 };
let employee = Object.assign( {}, user, { add: "dhaka", age: 35 } );
console.log( user ); //{ name: 'Nasir', age: 25 }
console.log( employee ); // { name: 'Nasir', age: 35, add: 'dhaka' }
//------------------------------------------//
let user1 = { name: "ahmed" };
let employee1 = Object.assign( user1, { permission: "can edit" } );
console.log( user1 ); // { name: 'ahmed', permission: 'can edit' }
console.log( employee1 ); //{ name: 'ahmed', permission: 'can edit' }
为什么user1对象获取属性：permission？
我将user1对象属性复制到employee1并添加了其他属性permission，所以permission应该只在employee1对象上找到，而不是在user1.
请指导我，我错过了什么？
回答
因为，Object.assign()has 语法，Object.assign(target, source)所以您user1用作目标。因此，使用空对象{}作为目标，以便对象合并到该目标中并且user1对象不会更改。
let user1 = {
name: "ahmed"
};
let employee1 = Object.assign({}, user1, {
permission: "can edit"
});
console.log(user1); // { name: 'ahmed' }
console.log(employee1); //{ name: 'ahmed', permission: 'can edit' }您甚至可以使用传播语法来实现这一点：
let user1 = {
name: "ahmed"
};
let employee1 = {
...user1,
...{ permission: "can edit" }
}
console.log(user1); // { name: 'ahmed' }
console.log(employee1); //{ name: 'ahmed', permission: 'can edit' }