Centre for Development of Advanced Computing Junior System Administrator Interview Questions and Answers

Java is a general-purpose programming language while JavaScript is a scripting language used for web development.

• Java is compiled while JavaScript is interpreted

• Java is statically typed while JavaScript is dynamically typed

• Java is used for developing desktop applications, web applications, and Android apps while JavaScript is used for web development

• Java code runs on a virtual machine while JavaScript code runs on a we...read more

Singleton design pattern restricts the instantiation of a class to one object.

• Ensures only one instance of a class exists

• Provides a global point of access to that instance

• Used when only one instance of a class is needed throughout the application

• Example: Database connection manager

Question on internal working of hashmap, multi-threading, DSA, and coding.

• HashMap is a data structure that stores key-value pairs and uses hashing to retrieve values quickly.

• Multi-threading is the ability of a CPU to execute multiple threads concurrently.

• DSA stands for Data Structures and Algorithms, which are fundamental concepts in computer science.

• Coding involves writing instructions in a programming language to cre

Event loop is a mechanism that allows non-blocking I/O operations in a single-threaded environment.

• Event loop is used in programming languages like JavaScript and Python.

• It manages the execution of multiple tasks by prioritizing them based on their priority level.

• It continuously checks for new events and executes them in a loop.

• It allows for efficient handling of I/O operations without blocking the main thread.

• It is co...read more

let, var and const are used to declare variables in JavaScript with different scoping rules and mutability.

• let and var are used to declare variables that can be reassigned later, but var has function scope while let has block scope.

• const is used to declare variables that cannot be reassigned and have block scope.

• Using const does not mean the value is immutable, only the variable reference is.

• let and const were introduc...read more

Program to find 2nd largest number in array

• Sort the array in descending order and return the 2nd element

• Initialize two variables, largest and secondLargest, and iterate through the array to find the two largest numbers

• Use a priority queue to keep track of the two largest numbers

Program to find the prefix of OL in an array of strings

• Loop through each string in the array

• Check if the first two characters are 'OL'

• If yes, add the string to a new array of prefixes

• Return the array of prefixes