Salesforce Apex Interview questions and answers in 2024 – Part I

This article aims to help you prepare for your Salesforce Interview, providing you with a detailed set of potential Salesforce Apex Interview questions and answers.

2. How to handle exceptions in Apex?

   try {
       // Code that may throw an exception
   } catch (Exception e) {
       // Exception handling code
   }

5. How can you make a class or method accessible by only a specific group of users?

   public with sharing class MyRestrictedClass {
       // Code here
   }

6. How to handle bulk operations in Apex?

   Trigger MyTrigger on MyObject__c (before insert) {
       List<MyObject__c> recordsToUpdate = new List<MyObject__c>();
       for (MyObject__c obj : Trigger.new) {
           // Perform bulk operations
           recordsToUpdate.add(obj);
       }
       update recordsToUpdate;
   }

9. How can you implement a custom controller for a Visualforce page?

   public class MyController {
       public String message { get; set; }

       public MyController() {
           message = 'Hello from the controller!';
       }
   }

Static Variable:

A static variable is shared among all instances of a class and retains its value throughout the lifetime of the application or until it is explicitly changed. It is often used for maintaining state information that needs to be common across instances of the class.

Example:

public class MyClass {
    public static Integer myStaticVariable = 0;

    public void incrementStaticVariable() {
        myStaticVariable++;
    }
}

Static Method:

A static method is a method that belongs to the class rather than to an instance of the class. It can be called using the class name, and it doesn’t require an instance of the class to be created.

Example:

public class MathOperations {
    public static Integer add(int a, int b) {
        return a + b;
    }
}

Purposes and Use Cases:

1. Shared State: Static variables allow you to maintain shared state information across instances of a class.
2. Utility Functions: Static methods are often used for utility functions that don’t depend on the state of an instance.
3. Constants: Constants, such as configuration values, can be declared as static variables.
4. Counters and Trackers: Static variables are useful for counters or trackers that need to persist across multiple instances.
5. Global Access: Static methods can be accessed globally without the need to create an instance of the class.

// Using the static variable and method
MyClass.myStaticVariable = 42;
MyClass.incrementStaticVariable();

// Using the static method
Integer result = MathOperations.add(10, 20);

In summary, static variables and methods in Apex provide a way to share data and behavior at the class level, rather than at the instance level. They are particularly useful when you want to maintain common state or have functionality that doesn’t depend on the specific instance of the class.

13. How can you schedule an Apex job to run at a specific time?

String jobId = System.schedule('MyScheduledJob', '0 0 2 * * ?', new MyScheduledClass());

@testSetup
static void setupTestData() {
    // Create test records
}

15. How do you make a field read-only in Apex?

Schema.DescribeFieldResult fieldResult = MyObject__c.MyField__c.getDescribe();
fieldResult.isUpdateable(); // Returns true if the field is updateable

@future(callout=true)
public static void myFutureMethod() {
    // Callout code here
}

17. How to prevent an Apex trigger from running recursively?

public class TriggerHandler {
    private static Boolean isExecuting = false;

    public static void myTriggerLogic() {
        if (!isExecuting) {
            isExecuting = true;
            // Trigger logic here
            isExecuting = false;
        }
    }
}

18. How can you query for all records modified in the last 7 days using SOQL in Apex?

List<MyObject__c> records = [SELECT Id, Name FROM MyObject__c WHERE LastModifiedDate = LAST_N_DAYS:7];

global class MyBatchClass implements Database.Batchable<SObject> {
    global Database.QueryLocator start(Database.BatchableContext BC) {
        // Query for records to process
        return Database.getQueryLocator('SELECT Id FROM MyObject__c');
    }

    global void execute(Database.BatchableContext BC, List<SObject> scope) {
        // Process records
    }

    global void finish(Database.BatchableContext BC) {
        // Finalize processing
    }
}

Resource : Apex Developer Guide