Are you preparing for a Salesforce Developer interview in 2023? Congratulations! As a Salesforce Developer, you play a vital role in designing and implementing customized solutions on the Salesforce platform. To help you succeed in your interview, we have compiled the 25 most frequently asked Salesforce Developer interview questions, along with their comprehensive answers. Let's dive in!
1. What is Apex in Salesforce?
Answer: Apex is a server-side programming language used in Salesforce to develop custom business logic, controllers, and extensions for Visualforce pages. It is similar to Java and allows developers to interact with Salesforce objects and data.
2. How can you prevent the creation of duplicate records in Salesforce?
Answer: To prevent duplicate records, you can use several methods:
Use validation rules to enforce unique field values.
Implement duplicate rules with matching criteria.
Utilize third-party apps available on the Salesforce AppExchange.
3. What is a Governor Limit in Salesforce?
Answer: Governor limits are runtime limits enforced by Salesforce to ensure the efficient use of shared resources and maintain system stability. They restrict the amount of data and code that can be processed in a single transaction.
4. How do you handle governor limits in Salesforce?
Answer: To handle governor limits efficiently:
Write efficient code to minimize SOQL queries and DML operations.
Use collections (lists, sets, maps) to bulkify your code.
Implement pagination for large data sets.
Consider asynchronous processing using Batch Apex or Queueable to handle long-running operations.
5. What is a Wrapper Class?
Answer: A Wrapper Class, in simple terms, is an object created in Apex – similar to a custom object but created in code. This data lives only in code during your transaction and does not consume database storage. It’s a data structure or an abstract data type that can contain different objects or collections of objects as its members.
6. What are the benefits of a Wrapper Class?
Answer: A Wrapper Class provides multiple benefits including:
The possibility of converting the JSON string into an object (and vice versa) with little effort.
Helping to combine different types of appropriate data and organizing it efficiently.
The ability to complete a variety of calculations during data organization.
Also, a Wrapper Class can be used in Lightning Web Component (LWC), AURA, and Visualforce.
7. How do you avoid "SOQL Queries in For Loops" in Apex?
Answer: Avoiding SOQL queries in For Loops is essential to prevent hitting governor limits. Instead of querying inside a loop, you can retrieve the data outside the loop and use collections (lists, sets, maps) to perform necessary operations.
8. How do you implement a one-to-many relationship between objects in Salesforce?
Answer: A one-to-many relationship can be implemented using a Master-Detail relationship or a Lookup relationship. In a Master-Detail relationship, the child record depends on the parent, while in a Lookup relationship, the child record is independent and points to a parent record.
9. What is SOQL?
Answer: SOQL stands for Salesforce Object Query Language, and as the name suggests it is the main language used for performing queries against the database. While it has a similar syntax to SQL, there are a few key differences, mainly that SOQL is exclusively used for queries (i.e. SELECT statements).
It is used to retrieve data from a single object, and potentially those directly related to it. SOQL can be used both within Apex code – to query records for consumption by said code – or via the API and tools which use it – such as in data loading tools.
10. Explain the use of the "try-catch" block in Apex?
Answer: A "try-catch" block is used for exception handling in Apex. It allows you to handle exceptions gracefully and prevents code from breaking unexpectedly.
11. How do you perform callouts to external services in Apex?
Answer: You can perform callouts to external services in Apex using the HTTP classes provided by Salesforce, such as HTTPRequest and HTTPResponse. These classes allow you to make HTTP requests and handle the response from external services.
12. What is a Test Class in Salesforce?
Answer: A Test Class in Salesforce is used to test the functionality and performance of Apex code. It ensures that the code behaves as expected and meets the specified requirements.
13. Explain the use of the "Test.startTest()" and "Test.stopTest()" methods in Apex unit testing.
Answer: The "Test.startTest()" and "Test.stopTest()" methods are used in Apex unit tests to separate the limits for testing from the limits of the actual code. They allow you to perform a new set of limits within these two methods, providing more accurate testing.
14. What is a Salesforce trigger?
Answer: A Salesforce trigger is a piece of Apex code that executes before or after specific data manipulation events, such as insert, update, delete, or undelete, on a Salesforce record. Triggers allow developers to define custom logic and actions that run in response to these events.
15. Explain the difference between a Trigger.old and Trigger.new in Salesforce.
Answer: Trigger.old represents the old version of the records before they were updated or deleted, while Trigger.new represents the new version of the records that will be updated or inserted.
16. What are the types of triggers in Salesforce based on the execution context?
Answer: Triggers in Salesforce can be categorized into two types based on the execution context:
Before Triggers: These triggers are executed before the data manipulation event and are often used for validation or modification of data before it is saved.
After Triggers: These triggers are executed after the data manipulation event and are used for tasks that need to be performed after the record has been saved, such as sending emails or creating related records.
17. How can you prevent recursive triggers in Salesforce?
Answer: Recursive triggers occur when a trigger update or insert operation triggers another trigger, causing an infinite loop. To prevent this, you can use a static Boolean variable or a static Set to keep track of the trigger execution and ensure that the trigger logic only runs once per transaction.
18. What is Batch Apex, and when should you use it?
Answer: Batch Apex is used to process large sets of records asynchronously. It is suitable for operations that can't be done synchronously due to Salesforce's governor limits. You should use Batch Apex when working with large data volumes or performing complex data operations.
19. What is the purpose of the @future annotation in Apex?
Answer: The @future annotation in Apex is used to define methods that are asynchronous and run in the background. These methods can be executed in a separate transaction after the current transaction completes.
20. What are the different types of sandboxes available in Salesforce?
Answer: Salesforce offers various types of sandboxes to facilitate development and testing:
Developer Pro Sandbox
Partial Copy Sandbox
21. Explain the difference between a Full Copy Sandbox and a Partial Copy Sandbox.
Answer: A Full Copy Sandbox is a complete replica of the production environment, including all data and metadata. In contrast, a Partial Copy Sandbox contains a subset of production data and all metadata. Full Copy is ideal for comprehensive testing, while Partial Copy is suitable for performance and functional testing.
22. What is SLDS?
Answer: The Salesforce Lightning Design System (SLDS) is the user interface design framework used by Salesforce for designing, styling, and building all aspects of Salesforce Lightning.
As developers, we can utilize the SLDS provided CSS styles or component markup templates to build custom components which provide a consistent UI with the rest of the platform. SLDS also provides guidelines around accessibility, language guidance, and icons.
23. What are Salesforce Lightning Web Components (LWC)?
Answer: Salesforce Lightning Web Components (LWC) are a modern and lightweight framework for building web components on the Salesforce Lightning Platform. LWC is based on web standards and offers a seamless development experience with enhanced performance and productivity.
24. What are the benefits of using LWC in Salesforce development?
Answer: The benefits of using LWC include:
Improved performance and faster load times.
Enhanced code reuse and maintainability.
Seamless integration with Salesforce data and services.
Better compatibility with future web standards.
25. How can you communicate between components in LWC?
Answer: LWC provides two main ways to communicate between components:
Parent-to-Child Communication: Pass data from a parent component to a child component using properties (attributes).
Child-to-Parent Communication: Use custom events to send data or trigger actions from a child component to a parent component.