How can I resolve and troubleshoot the issue of “attempt to de-reference a null Object” during the development of an apex class?

 In the context of Salesforce, you can troubleshoot and resolve this particular issue in apex by using the steps which are given below:-

Identify the null object

Try to determine which object or variable is causing the error. This particular test can be done by examining the error message.

Checking for the null values

Try to review the code to identify where the null object is being accessed or referenced. You can utilize the conditional statement to ensure that the Object should not be null.

Handle null class

You can try to execute appropriate error handling or defensive programming techniques for handling the null cases gracefully.

Here is one example given of how you can use a null check to ensure that the “acc” variable should not be null before the time of accessing its “name” property:-

// Example code snippet demonstrating how to handle null references

Account acc = [SELECT Id, Name FROM Account LIMIT 1];
If (acc != null) {
    // Check if the account is not null before accessing its properties
    System.debug(‘Account Name: ‘ + acc.Name);
} else {
    // Handle the case where the account is null
    System.debug(‘No account found.’);
}