Cognizant SAP PI Consultant Interview Questions and Answers

Life Cycle hooks in LWC are methods that allow you to interact with the component at specific stages of its lifecycle.

• There are four main life cycle hooks in LWC: connectedCallback, disconnectedCallback, renderedCallback, and errorCallback.

• connectedCallback is called when a component is inserted into the DOM.

• disconnectedCallback is called when a component is removed from the DOM.

• renderedCallback is called after the com...read more

There are multiple ways to communicate between components in Salesforce, including using events, public properties, and Apex methods.

• Using events to communicate between components

• Passing data through public properties

• Invoking Apex methods to share data

Yes, future methods can be called from a batch class in Salesforce.

• Future methods can be called from batch classes to perform asynchronous processing.

• This can be useful for offloading long-running tasks to future methods to avoid hitting governor limits.

• Example: Calling a future method from a batch class to update records in Salesforce asynchronously.

The @track decorator in Salesforce is used to track changes to a property in a Lightning web component.

• Used to make a property reactive and trigger re-renders when its value changes

• Not mandatory but recommended for properties that need to be reactive

• Use @track when you want changes to a property to be reflected in the UI

APEX CPU Limit Exceeded error happens when code consumes too much CPU time. Best practices include optimizing code, reducing loops, and using asynchronous processing.

• Avoid using nested loops and optimize code for better performance

• Use asynchronous processing like @future or Queueable to offload CPU intensive tasks

• Limit the use of SOQL queries inside loops to reduce CPU consumption

Mixed DML Exception occurs when DML operations are performed on setup and non-setup objects in a single transaction.

• Occurs when DML operations are performed on both setup and non-setup objects in a single transaction

• Setup objects include User, Profile, PermissionSet, etc.

• Non-setup objects include custom objects, standard objects like Account, Contact, etc.

The code will output 'undefined' because variable 'a' is hoisted within the function.

• Variable 'a' is hoisted to the top of the function scope, so when 'console.log(a)' is called, 'a' is undefined.

• To fix this, move the declaration of 'var a=2;' above the 'console.log(a);' statement.

SOQL query to fetch description field from Account and reason for inability to filter

• SOQL query: SELECT Description FROM Account

• Description field is not filterable because it is a long text field

• Long text fields cannot be filtered in SOQL queries