JavaScript is bound to (2 null and undefined)
- 2021-06-28 08:21:39
- OfStack
null
null means "empty".
Using typeof; //Object;He is a special object.
The null type has only one member of itself.He does not contain attributes or methods.
undefined
undefined also means "empty".
Using typeof; //undefined;It means he is of undefined type.
The undefined type contains only one member of itself, and it does not contain attributes and methods.
summary
null and undefined can be in a different sense, for example, they can be converted to Boolean values to represent false.
Neither null nor undefined can use.And [] for member values, so you should first determine whether the object is null or undefined.