Opcommerce Online Catalogue Specialist Interview Questions and Answers

Event bubbling is the propagation of an event from the innermost child element to the outermost parent element.

• Events triggered on a child element will also trigger on its parent elements

• The event travels up the DOM tree until it reaches the document object

• Can be stopped using event.stopPropagation()

• Can be useful for event delegation

The .on('click',function() is a more flexible method than .click(function())

• The .on() method can handle multiple events and selectors

• The .click() method can only handle one event and one selector

• The .on() method can also handle dynamically added elements

• The .click() method cannot handle dynamically added elements

Function to check if two strings are anagram or not

• Create two character arrays from the strings

• Sort the arrays

• Compare the sorted arrays

Function to determine the order of integers in an array.

• Check first and last element to determine if increasing or decreasing

• Check for inflection point to determine if order changes

• Return order type as string

Optimize images, minify code, reduce HTTP requests, use caching, and lazy loading.

• Optimize images using compression and appropriate file formats

• Minify code to reduce file size and improve load times

• Reduce HTTP requests by combining files and using sprites

• Use caching to store frequently accessed data locally

• Implement lazy loading to defer loading of non-critical resources

Design a database schema for a movie site with user ratings and recommendations.

• Create tables for movies, users, ratings, and recommendations

• Use foreign keys to link tables

• Include columns for movie genre and user watch history

• Algorithm for recommendations can use user watch history and ratings to suggest similar movies

Function to simulate dice roll with equal probability without using random function

• Use a toss function that returns either 0 or 1 with equal probability

• Call the toss function 3 times and convert the result to a binary number

• If the binary number is greater than 0 and less than or equal to 6, return it

• If the binary number is greater than 6, repeat the process

Query to fetch duplicate email from table

• Use GROUP BY and HAVING clause to filter out duplicates

• SELECT email, COUNT(*) FROM table_name GROUP BY email HAVING COUNT(*) > 1;

• This will return all the duplicate emails in the table