null is often used to explicitly check if a value is absent:
null and undefined are similar in meaning but have distinct use cases:
- null: Represents the intentional absence of a value, often assigned explicitly by the programmer.
- undefined: Represents the absence of a value when a variable hasn't been assigned any value, function doesn't return a value, or an object property doesn't exist.
- When checking for equality, remember that null == undefined is true. However, they are not strictly equal (null !== undefined).
- Be careful when accessing properties of variables set to null, as this can result in errors.