Essential Java Interview Questions and Answers

Java Super Keyword

Question: Explain the functionality of the super keyword in Java.

Answer: The super keyword refers to the immediate parent class object. It is used to:

  • Access parent class data members hidden by child class data members.
  • Call parent class methods when overridden in the child class.
  • Invoke the parent class constructor using super().

Throw vs Throws in Java

Question: Differentiate between throw and throws keywords in Java.

Answer: throw is used inside a method or block to explicitly throw

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ARM LPC1768 Embedded C Programming and Architecture

ARM LPC1768 Embedded C Programming Examples

LED Blinking Program for ARM LPC1768

#include <LPC17xx.h>

void delay() {
    for(int i=0; i<1000000; i++);
}

int main(void) {
    LPC_GPIO2->FIODIR |= (1<<0); // Set P2.0 as output
    while(1) {
        LPC_GPIO2->FIOSET = (1<<0); // LED ON
        delay();
        LPC_GPIO2->FIOCLR = (1<<0); // LED OFF
        delay();
    }
}

Switch Controlled LED Interfacing

#include <LPC17xx.h>

int main(void) {
    LPC_GPIO2-
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Node.js and Express Backend Development Handbook

Express Framework Fundamentals

The Node.js web framework provides a structured pipeline from top to bottom:

  • Routing system
  • Middleware pipeline
  • Response utilities
  • Template integration (Pug, etc.)

The standard flow follows: Request → Middleware → Route → Response.

Middleware Pipeline

Middleware functions run before the final response. The function signature is (req, res, next). These functions can:

  • Modify the req or res objects.
  • Stop the request using res.send().
  • Pass control using next().

Note: If neither

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Fundamental Concepts of Computing and Programming

Definition and Characteristics of a Computer

A computer is an electronic device that accepts data (input), processes it according to a set of instructions (program), stores it, and produces meaningful information (output).

What is a Computer?

A computer can be defined as: “An electronic machine that takes input, processes it under the control of a program, and produces output while storing the data for future use.”

Key Characteristics of a Computer

Computers have several important characteristics

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Windows Server Administration: Essential PowerShell & Tasks

Remote PowerShell

Enter-PSSession -ComputerName AcmeDC
Exit-PSSession

Create Security Group

New-ADGroup -Name "NAME" -GroupScope Global -Path "OU=Hamilton,DC=acme,DC=com"

Create Folder and Share

  • Folder: New-Item -Path "C:\Corporate\NAME" -ItemType Directory
  • Share: New-SmbShare -Name "NAME" -Path "C:\Corporate\NAME" -FullAccess "Everyone"

NTFS Permissions (icacls)

  • Full Control: icacls "PATH" /grant "ACME\GROUP:(OI)(CI)F"
  • Modify: icacls "PATH" /grant "ACME\GROUP:(OI)(CI)M"
  • Read & Exec: icacls "PATH" /grant
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PPS SEMII

1. Short note on String

A String is a one-dimensional array of characters terminated by a null(‘\0’). Each character in the array occupies one byte of memory, and the last character
must always be null(‘\0’). The termination character (‘\0’) is important in a string to identify where the string
ends. 

Syntax:

charstring_name[size];

char name[10]; [0] [1] [2] [3] [4] [5] [6] [7] [8] [9] 

 name[10           D A    R    S   H   A   N \0 

Declaration and Initialisation


You can declare and

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