A NullPointerException is a runtime exception that is thrown when an application attempts to use an object reference that has a null value. To avoid this exception, you need to make sure that the object reference is not null before you use it.
To check if a string is equal to null in Java, you can use the == operator.
In Python, the "null" object is called None.
There are a few possible reasons that json_decode() might return NULL when given what appears to be valid JSON.
Read this JavaScript tutorial and get relevant information about the differences between null and undefined data types. Find out their similarities as well.
There are several reasons why an @Autowired field in a Spring bean might be null: