Race2cloud Technologies Salesforce COM Developer Interview Questions and Answers for Freshers

Mcqs on javascript,. 1 coding question

Coding is based scenario question , we have to write the code in paper. There is 1 hour time to complete the coding test.

Q1. I am unable to attend the second round.
Add your answer

Round duration - 90 minutes
Round difficulty - Easy

Timing was 10:00 AM. Platform was good.

Q1. 
Subarray With Given Sum Problem Statement
Given an array ARR of N integers and an integer S, determine if there exists a contiguous subarray within the array with a sum equal to S. If such a subarray exis...read more
Ans. 
Given an array of integers, find a subarray with a given sum S.
• Iterate through the array while keeping track of the current sum and start index.

• Use a hashmap to store the sum and its corresponding index.

• If the current sum - S is found in the hashmap, a subarray with sum S exists.

• Return the start index and current index as the end index.
Answered by AI
Add your answer
Q2. 
Remove Consecutive Duplicates Problem Statement
Given a string S, your task is to recursively remove all consecutive duplicate characters from the string.
Input:
String S
Output:
Output string
Constr...read more
Ans. 
Recursively remove consecutive duplicate characters from a string.
• Use recursion to check if the current character is the same as the next character, if so skip the next character

• Base case: if string length is 1, return the string

• Example: Input: 'aabbc' Output: 'abc'
Answered by AI
Add your answer

Q1. Rate yourself in js, node js, react, MongoDB (separately)
Add your answer
Q2. Typeof null, typeof undefined, typeof {}, typeof NaN
Add your answer
Q3. What changes came in es6
Ans. 
ES6 introduced several new features and improvements to JavaScript, making it more powerful and efficient.
• Arrow functions for more concise syntax

• Let and const for block-scoped variables

• Classes for easier object-oriented programming

• Template literals for easier string interpolation

• Default parameters and rest parameters for function arguments

• Destructuring assignment for easier data extraction

• Promises for asynchronous prog
Answered by AI
Add your answer
Q4. This keyword, closures, hoisting
Add your answer
Q5. Are let and cont variables hoisted?
Ans. 
Yes, let and const variables are hoisted but not initialized.
• let and const variables are hoisted to the top of their block scope, but they are not initialized until the actual line of code is executed.

• This means that you cannot access a let or const variable before it is declared in the code.

• For example, trying to access a let variable before it is declared will result in a ReferenceError.
Answered by AI
Add your answer
Q6. What is global context
Ans. 
Global context refers to the overall environment or setting in which something exists or operates.
• Global context encompasses all variables, functions, and objects that are accessible throughout an entire program.

• It can be thought of as the 'big picture' view of a program's execution.

• In web development, global context includes the window object in JavaScript.
Answered by AI
Add your answer
Q7. What is temporal deadzone
Ans. 
Temporal dead zone is a period during the variable creation process where accessing the variable results in a ReferenceError.
• Occurs when trying to access a variable before it has been declared with let or const

• Happens due to the variable being in the temporal dead zone until it is declared

• Example: accessing a variable before its declaration will result in a ReferenceError
Answered by AI
Add your answer
Q8. What is modules? types of modules in nodejs
Ans. 
Modules in Node.js are reusable blocks of code that encapsulate related functionality.
• Modules in Node.js can be built-in modules like fs (file system) or third-party modules like express.

• Modules help in organizing code into separate files for better maintainability and reusability.

• Modules can be imported using the require() function in Node.js.
Answered by AI
Add your answer
Q9. Index in mongodb, why we need index, is index good or bad?
Ans. 
Indexes in MongoDB improve query performance by allowing the database to quickly locate and retrieve specific documents.
• Indexes help to speed up query performance by allowing the database to quickly locate specific documents based on the indexed fields.

• Without indexes, MongoDB would have to perform a collection scan, which can be slow and resource-intensive.

• Indexes can be created on single fields or compound fields to ...read more
Answered by AI
Add your answer
Q10. What are hooks , use of useRef
Ans. 
Hooks are a feature in React that allow you to use state and other React features in functional components. useRef is a hook that allows you to create a mutable object that persists for the lifetime of the component.
• Hooks are used to add state and lifecycle methods to functional components in React

• useRef is used to create a mutable reference that persists between renders

• useRef can be used to access DOM elements directl
Answered by AI
Add your answer
Q11. Fs module, http module, worker thread?
Add your answer
Q12. Why we use mongoose not mongodb driver?
Ans. 
Mongoose is an Object Data Modeling (ODM) library for MongoDB that provides a higher level of abstraction and simplifies interactions with the database.
• Mongoose provides schema validation which helps maintain data integrity.

• Mongoose simplifies querying and data manipulation with built-in functions.

• Mongoose supports middleware functions for pre and post processing of data operations.
Answered by AI
Add your answer

Q1. Find the second most occurrence of string.
Ans. 
Find the second most occurrence of string in an array of strings.
• Create a dictionary to store the count of each string in the array

• Sort the dictionary by count in descending order

• Return the key of the second element in the sorted dictionary
Answered by AI
Add your answer

There was an OA on hackerearth of an hour. In that there were 20 MCQs and two DSA questions easy to medium on Heap, Hashmap and Subarray

Q1. Asked about previous worked project in last company
Add your answer
Q2. Asked one medium DSA question (DNA sequencing) and asked to design some schema
Add your answer
Q3. Asked one puzzle If there are 1000 bottles and one is poisonous, a rat will diw after one hour of drinking and you have only one hour to find out which bottle is poisonous, How many minimum rats you need ?
Add your answer