Apex Class

1. Difference between with sharing and without sharing in salesforce

Ans. By default, all Apex executes under the System user, ignoring all CRUD, field-level, and row-level security (that is always executes using the full permissions of the current user).

with sharing:

Enforcing the User’s Permissions, Sharing rules and field-level security should apply to the current user.

For example:

public with sharing class sharingClass {

         // Code here

}

without sharing:

Not enforced the User’s Permissions, Sharing rules and field-level security.

For example:

public without sharing class noSharing {

        // Code here

}

2. Access Modifiers  in salesforce 

Ans.

– private: This method/variable is accessible within the class it is defined.

– protected: This method/variable is also available to any inner classes or sub-classes. It can only be used by instance methods and member variables.

– public: This method/variable can be used by any Apex in this application namespace.

– global: this method/variable is accessible by all Apex everywhere.

• All methods/variable with the web-service keyword must be global.

– The default access modifier for methods and variables is private.

3. Exceptions Statements  in salesforce 

Ans.

Throw: signals that an error has occurred and provides an exception object.

• Try: identifies the block of code where the exception can occur.

• Catch: identifies the block of code that can handle a particular exception. There may be multiple catch blocks for each try block.

• Finally: optionally identifies a block of code that is guaranteed to execute after a try block.

Exception Example:

public class OtherException extends BaseException {}

Try{

     //Add code here

     throw new OtherException(‘Something went wrong here…’);

} Catch (OtherException oex) {

     //Caught a custom exception type here

} Catch (Exception ex){

     //Caught all other exceptions here

}

4. What is the difference between a standard controller and custom controller ?

     Ans: standard controller inherits all the standard object properties, standard button functionalities can be directly used. Custom controller defines custom functionalities, a standard controller can be extended to develop custom functionalities using keyword "extensions"

5. How to get current logged in users id in apex ?

Ans. Userinfo.getuserid()

6. How to fire dynamic query in SOQL?

Ans. Database.query('select name from account');

7. How can you lock records in apex?

Ans. Use For update in query to lock the record. For example: [select id,name from contact limit 10 For update];

8. How can you access custom label in apex ?

Ans. System.Label.LabelNamehere

9. What is search layout? 

Ans . When we click on lookup field the results which is shown is called search layout.

10. What is mini page layout ? 

Ans. For lookup fields on record detail page we see a link, whenever we put cursor on that link we see a popup window which displays few fields.