How to solve “System.NullPointerException: Attempt to de-reference a null object” in Salesforce apex class?

Hi Sushant

“System.NullPointerException: Attempt to de-reference a null object”
This is a very common error message which occurs when your object/list is not initialised (allocated memory). So when say not initialised means following:

In order to use the non primitive data type in the code we have initialised the memory to those data types. For example:

I want to use the Account object in my apex class, so I have allocate a memory to that object. So to do that I have to write:

Account accountObj = new Account(); // allocating memory to the account.

Similarly in case of list:

list<Account> accountList  = new list<Account>(); // allocating memory to list of accounts.

So in your code make sure you have allocated the memory to your non primitive data types, else you will ran into same error.

Hope this helps, if not please attach your code.

Thanks.