In JavaScript, objects, variables, properties, and methods can be undefined.
Additionally, empty objects can have the value null.
This can make it challenging to determine if an object is empty.
You can check if an object exists by testing whether its type is undefined.
| if (typeof myObj === “undefined”) |
However, you cannot directly test if an object is null, as doing so will throw an error if the object is undefined.
| if (myObj === null) |
To resolve this issue, you must test if an object is neither null nor undefined.
However, this can still result in an error.
| if (myObj !== null && typeof myObj !== “undefined”) |
Because of this, you must first test for undefined before checking for null.
| if (typeof myObj !== “undefined” && myObj !== null) |