Top 10 interviews questions on Salesforce Annotations with coding examples

Top 10 interviews questions on Salesforce Annotations with coding examples

On January 8, 2024, Posted by , In Salesforce, With Comments Off on Top 10 interviews questions on Salesforce Annotations with coding examples

List of Questions

  • Explain the purpose of the @AuraEnabled annotation in Salesforce and provide a complex example.
  • What is the @TestSetup annotation and how does it benefit the testing process in Salesforce? Provide a detailed example.
  • Can you provide a complex example of a test class in Apex using the @isTest annotation?
  • Describe a scenario where the @Future annotation would be critically important. Provide an advanced example.
  • How does the @ReadOnly annotation affect SOQL query limits in Apex? Provide a complex use case.
  • What are the RESTful service annotations in Apex and how are they used? Provide a detailed example including multiple HTTP methods.
  • Why would you use the @Deprecated annotation in your Apex code? Provide an example with a legacy and a new method.
  • In what situation would you use the @InvocableMethod annotation? Provide a comprehensive example.
  • Explain how the @TestSetup annotation improves efficiency in writing test classes. Can you write a sample test class using this annotation with complex setup and multiple test methods?
  • Discuss how annotations contribute to code readability and maintenance in Salesforce development. Give specific examples.

Here is the list of top 10 interview questions and answers with more detailed and complex coding examples for Salesforce annotations. We need to know how many types of annotations are present in Salesforce before reading the following interview questions.

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Question: Explain the purpose of the @AuraEnabled annotation in Salesforce and provide a complex example.

Answer: The @AuraEnabled annotation is used to expose Apex methods to Lightning components, enabling server-side logic to be accessible from the client side. This is essential for dynamic data operations within Lightning components. For example, consider an Apex class that retrieves detailed account information based on certain criteria:

public class AccountManager {
    @AuraEnabled(cacheable=true)
    public static List<Account> getAccountsByIndustry(String industry) {
        return [SELECT Id, Name, Industry, AnnualRevenue 
                FROM Account 
                WHERE Industry = :industry 
                LIMIT 100];
    }
}

Here, the @AuraEnabled annotation makes getAccountsByIndustry callable from a Lightning component, allowing for dynamic retrieval of account data based on the industry parameter.

Question: What is the @TestSetup annotation and how does it benefit the testing process in Salesforce? Provide a detailed example.

Answer: The @TestSetup annotation is used in test classes to create data that can be shared across multiple test methods. This reduces redundancy and improves test performance by setting up necessary data only once.

For instance:

@isTest
private class AccountTest {
    @TestSetup
    static void setup() {
        List<Account> accounts = new List<Account>();
        for(Integer i = 0; i < 10; i++) {
            accounts.add(new Account(Name='TestAccount' + i));
        }
        insert accounts;
    }

    @isTest static void testMethod1() {
        List<Account> accounts = [SELECT Name FROM Account];
        System.assertEquals(10, accounts.size());
    }
}

Here, @TestSetup creates 10 test accounts, and testMethod1 verifies the creation, illustrating the reuse of test setup data.

Question: Can you provide a complex example of a test class in Apex using the @isTest annotation?

Example Answer:

@isTest
private class ComplexTestClass {
    @isTest static void testComplexLogic() {
        // Complex setup for testing
        Account testAccount = new Account(Name='TestAccount');
        insert testAccount;

        Contact testContact = new Contact(LastName='Doe', AccountId=testAccount.Id);
        insert testContact;

        // Asserts and complex test logic
        Contact retrievedContact = [SELECT AccountId FROM Contact WHERE Id = :testContact.Id];
        System.assertEquals(testAccount.Id, retrievedContact.AccountId);
    }
}

This test class demonstrates a more complex setup involving related records (Account and Contact) and tests their relationship.

Question: Describe a scenario where the @Future annotation would be critically important. Provide an advanced example.

Answer: The @Future annotation is critical for executing long-running operations asynchronously, especially when dealing with callouts or operations that exceed governor limits. For example, consider an asynchronous method that makes a callout to an external service for updating multiple records:

public class AsyncUpdater {
    @Future(callout=true)
    public static void updateExternalData(List<Id> recordIds) {
        // Complex logic for callout and updating records
        Http http = new Http();
        HttpRequest request = new HttpRequest();
        // Set request properties
        HttpResponse response = http.send(request);

        // Parse response and update records
    }
}

This method demonstrates the use of @Future for handling HTTP callouts and processing the response asynchronously, thus not blocking the main execution flow.

Question: How does the @ReadOnly annotation affect SOQL query limits in Apex? Provide a complex use case.

Answer: The @ReadOnly annotation increases the governor limits for SOQL queries in Visualforce pages, allowing the retrieval of up to 1,000,000 records and a higher heap size. This is particularly useful in scenarios requiring large data sets, like generating complex reports. For example:

public with sharing class ReportGenerator {
    @ReadOnly
    public static List<Opportunity> generateOpportunityReport(String fiscalYear) {
        return [SELECT Id, Name, CloseDate, Amount 
                FROM Opportunity 
                WHERE FiscalYear = :fiscalYear 
                LIMIT 100000];
    }
}

In this method, a large set of Opportunity records is fetched for a given fiscal year, which would normally exceed standard SOQL query limits.

Question: What are the RESTful service annotations in Apex and how are they used? Provide a detailed example including multiple HTTP methods.

Example Answer:

@RestResource(urlMapping='/MyResource/*')
global with sharing class MyRestService {
    @HttpGet
    global static String doGet() {
        // Handle GET request
        return 'GET Response';
    }

    @HttpPost
    global static String doPost() {
        // Handle POST request
        return 'POST Response';
    }

    @HttpPut
    global static String doPut() {
        // Handle PUT request
        return 'PUT Response';
    }

    @HttpDelete
    global static String doDelete() {
        // Handle DELETE request
        return 'DELETE Response';
    }
}

Question: Why would you use the @Deprecated annotation in your Apex code? Provide an example with a legacy and a new method.

Answer: The @Deprecated annotation is used to mark methods or classes as obsolete. This informs other developers that a newer, preferred method or class should be used. For example:

public class AccountService {
    @Deprecated
    public static List<Account> getOldAccounts() {
        // Old implementation
    }

    public static List<Account> getNewAccounts() {
        // New implementation
    }
} 

Here, getOldAccounts is marked as deprecated, guiding developers to use the getNewAccounts method instead.

Question: In what situation would you use the @InvocableMethod annotation? Provide a comprehensive example.

Answer: The @InvocableMethod annotation is used when you need to expose an Apex method to be called from Salesforce Process Builder or Flow. For instance:

public class ApprovalProcessHandler {
    @InvocableMethod
    public static void approveRecords(List<Id> recordIds) {
        List<Approval.ProcessSubmitRequest> approvalRequests = new List<Approval.ProcessSubmitRequest>();
        for (Id recordId : recordIds) {
            Approval.ProcessSubmitRequest req = new Approval.ProcessSubmitRequest();
            req.setObjectId(recordId);
            approvalRequests.add(req);
        }
        // Process approvals
        List<Approval.ProcessResult> results = Approval.process(approvalRequests);
        // Handle results
    }
}

In this example, approveRecords is an invocable method that can be triggered via Process Builder to handle bulk record approvals.

Question: Explain how the @TestSetup annotation improves efficiency in writing test classes. Can you write a sample test class using this annotation with complex setup and multiple test methods?

Example Answer:

@isTest
private class ComplexTestSetup {
    @TestSetup
    static void setupData() {
        Account acc = new Account(Name='TestAccount');
        insert acc;

        List<Contact> contacts = new List<Contact>();
        for (int i = 0; i < 5; i++) {
            contacts.add(new Contact(LastName='TestContact' + i, AccountId=acc.Id));
        }
        insert contacts;
    }

    @isTest static void testMethod1() {
        List<Contact> contacts = [SELECT Name FROM Contact];
        System.assertEquals(5, contacts.size());
    }

    @isTest static void testMethod2() {
        Account acc = [SELECT Name FROM Account WHERE Name='TestAccount'];
        System.assertNotEquals(null, acc);
    }
} 

This test class demonstrates a complex setup with an Account and multiple Contacts. The setup data is then reused in multiple test methods.

Question: Discuss how annotations contribute to code readability and maintenance in Salesforce development. Give specific examples.

Answer: Annotations in Salesforce significantly enhance code readability and maintainability. For instance, @AuraEnabled clearly indicates that an Apex method is intended for use with a Lightning component, which aids in understanding the context of its usage. Similarly, the @isTest annotation segregates test code from production code, making it clear which parts of the codebase are for testing purposes. The @Deprecated annotation alerts developers to avoid using outdated methods and opt for newer ones, thereby aiding in code evolution and maintenance.

For example:

public class AccountHelper {
    @Deprecated
    public static void oldAccountMethod() {
        // Old implementation
    }

    public static void newAccountMethod() {
        // New implementation
    }
}

Here, the use of @Deprecated clearly marks the transition from an old method to a new one, guiding developers in maintaining and updating the codebase.

These expanded answers provide a deeper understanding of Salesforce annotations and their practical applications, demonstrating the candidates’ proficiency in Salesforce development.

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