RRB JE CBT2 : EXPERT
11 Jun

COMPUTER FUNDAMENTALS, PROGRAMMING IN C/C++, NETWORKING, INTERNET, DATABASES AND MS OFFICE NOTES

STRING FUNCTIONS IN C/C++

String functions are predefined library functions used to manipulate and process strings.

strlen()

strlen() returns the length of a string, excluding the null character.

strcat()

strcat() concatenates or joins two strings into a single string.

strcmp()

strcmp() compares two strings and determines whether they are equal or which string is lexicographically greater.

strcpy()

strcpy() copies one string into another string.

strchr()

strchr() searches for the first occurrence of a character in a string.

strrchr()

strrchr() searches for the last occurrence of a character in a string and returns a pointer to that position.

strstr()

strstr() searches for the first occurrence of a substring within a string.

strtok()

strtok() divides a string into smaller tokens using a specified delimiter.


JAVA APPLETS

An Applet is a small application designed to perform a specific task within a larger program or environment.A Java applet is a program written in the Java programming language and designed to run inside a web page.

Characteristics

  • Performs a specific task
  • Lightweight application
  • Easily accessible
  • Auxiliary in nature
  • Does not function as a full-featured standalone application

Java is commonly used to create applets.


INTEGER DATA TYPE (int)

The int data type is used for storing integer values.Depending on programming language implementation and system architecture, the range may vary.

Minimum Guaranteed Range

For a 16-bit integer:

−32767 to 32767

For a 32-bit integer:

−2147483647 to 2147483647



FILE TRANSFER PROTOCOL (FTP)

FTP (File Transfer Protocol) is a standard Internet protocol used for transferring files between computers over TCP/IP networks.FTP follows a client-server architecture.

Functions of FTP

  • Upload files
  • Download files
  • Delete files
  • Rename files
  • Move files
  • Copy files

FTP supports the transfer of both text files and binary files.FTP uses separate command and data connections to ensure reliable file transfer.


ZIP DRIVE

A Zip Drive is a data storage device introduced by Iomega in 1994.It provided greater storage capacity than traditional floppy disks and was widely used for backup and data transfer purposes.

Characteristics

  • Portable storage medium
  • Used for backup operations
  • Used for transferring data between systems
  • Hardware storage device

Its popularity declined after the introduction of:

  • CD-RW
  • DVD
  • USB Flash Drive

EMAIL ADDRESS STRUCTURE

An email address consists of two main components separated by the @ symbol.

Local Part

The local part uniquely identifies the user.

Example:In

abhishek@example.com

abhishek is the local part.

Domain Part

The domain identifies the email service provider or host server.Example:In

abhishek@example.com

example.com is the domain.


DATA STRUCTURES

Data structures are classified into Primitive and Non-Primitive data structures.

Primitive Data Structures

Primitive data structures are simple data types that cannot be further divided.Examples:

  • Integer
  • Real
  • Boolean
  • Character

Non-Primitive Data Structures

Non-primitive data structures are divided into:

Linear Data Structures

Elements are arranged sequentially.Examples:

  • Array
  • Linked List
  • Stack
  • Queue

Non-Linear Data Structures

Elements are not arranged in sequence.Examples:

  • Tree
  • Graph

PROGRAM CONTROL STATEMENTS

return

The return statement terminates a function and transfers control back to the calling function.It may also return a value to the calling function.

goto

The goto statement transfers program control to a labeled statement.Although available, its use is generally discouraged because it can make programs difficult to understand and maintain.

switch

The switch statement is used for multi-way decision making and selecting one among multiple code blocks.It does not transfer control back to the calling function.


SQL UPDATE COMMAND

The UPDATE statement is used to modify existing records in a database table.

Syntax

UPDATE Students
SET FirstName='Ramu'
WHERE FirstName='Siva';

Purpose

  • Updates existing records
  • Modifies selected rows based on a condition
  • Uses the WHERE clause to specify affected records

LINKED LIST OPERATIONS

A linked list supports several fundamental operations.

Traversal

Traversal means visiting every node in the linked list one by one.

Insertion

Insertion involves adding a new node at the beginning, middle, or end of the list.

Deletion

Deletion removes a node from the linked list by modifying links between nodes.Traversal, insertion, and deletion are all standard linked list operations.


CONCEPT KEYBOARD

A Concept Keyboard is a programmable keyboard commonly used in retail stores, restaurants, and service environments.Keys can be customized to perform specific functions or commands.

Features

  • Graphic-based keyboard
  • Highly customizable
  • Improves operational speed
  • Commonly used in POS systems

Each key may represent:

  • Products
  • Services
  • Menu items
  • Commands

ASSEMBLER, COMPILER AND INTERPRETER

Assembler

An assembler converts assembly language instructions into machine code.Examples of mnemonic instructions:

  • ADD
  • SUB

The resulting machine code can be directly understood by the computer.

Compiler

A compiler translates an entire high-level language program into object code before execution.

Interpreter

An interpreter translates and executes source code line by line.


COMPUTER NETWORKS

LOCAL AREA NETWORK (LAN)

A Local Area Network (LAN) connects computers within a limited geographical area.

Characteristics

  • Usually within a building or campus
  • Coverage up to approximately 1 km
  • Controlled by a single organization
  • Facilitates resource sharing

Technologies Used

  • Ethernet
  • Token Ring

LAN allows sharing of:

  • Software
  • Hardware resources
  • Data

METROPOLITAN AREA NETWORK (MAN)

A Metropolitan Area Network (MAN) covers a larger area than a LAN.

Characteristics

  • Connects nearby offices
  • Covers an entire city
  • Can be public or private

WIDE AREA NETWORK (WAN)

A Wide Area Network (WAN) connects computers over very large geographical distances.

Characteristics

  • Connects cities and countries
  • Uses leased communication lines
  • Managed by multiple organizations

NETWORK DEVICES

Gateway

A gateway connects multiple networks and allows communication between different networks.It acts as the entry and exit point of a network.

Router

A router directs traffic between networks.

Switch

A switch forwards data only to the intended destination device.

Hub

A hub connects multiple devices and broadcasts incoming data to all connected devices.

Bridge

A bridge connects two subnetworks.

Repeater

A repeater regenerates weak signals and extends transmission distance.

Modem

A modem performs:

  • Modulation
  • Demodulation

It converts digital data into analog signals and vice versa.


HOST

A server on the Internet is also called a Host.A host provides services and resources to clients within a network.


ADDRESS OPERATOR (&)

The & operator is known as the Address Operator.It returns the memory address of a variable.Example:

int x = 10;
&x

returns the memory location where x is stored.


MS OFFICE

MICROSOFT ACCESS

Microsoft Access is a Database Management System (DBMS) used for:

  • Storing data
  • Retrieving data
  • Managing databases

It is part of the Microsoft Office suite.


MICROSOFT EXCEL

F4 Key

The F4 key is used to toggle between different cell reference types while editing formulas.

TEXT() Function

The TEXT() function converts a numerical value into text according to a specified format.

Multiplication Formula

Excel uses the asterisk symbol (*) for multiplication.Example:

=A2*B2

MICROSOFT POWERPOINT

F5 Key

Pressing F5 starts a slideshow from the beginning.

Themes

Themes are applied through the Design Tab to change the visual appearance of a presentation.


MICROSOFT WORD

F2 Key

The F2 key is used to move selected text or graphics quickly from one location to another.


COLLATE IN PRINTING

Collation determines the arrangement of multiple copies of a multi-page document.

Collate ON

Pages are printed in complete document sets.Example:

1-2-3-4-5
1-2-3-4-5
1-2-3-4-5

Collate OFF

Pages are grouped together.Example:

1-1-1
2-2-2
3-3-3
4-4-4
5-5-5

SLEEP MODE

Sleep mode places a computer in a low-power operating state.

Characteristics

  • Applications remain active
  • Data remains stored in RAM
  • Quick system startup after wake-up
  • Suitable for short breaks

FILE HANDLING IN C

fscanf()

fscanf() reads formatted input data from a file stream.It functions similarly to scanf(), but reads data from a file rather than standard input.


OBJECT ORIENTED PROGRAMMING

Member Function

A member function is a function defined inside a class and operates on the objects of that class.


LABELED STATEMENT

A labeled statement consists of:

identifier:

It is commonly used with goto statements.


IMAGE EDITING

Cropping

Cropping refers to the removal of unwanted outer portions of an image.

Purpose

  • Remove unnecessary areas
  • Improve composition
  • Focus attention on important content

COMPUTER HARDWARE COMPONENTS

Arithmetic Logic Unit (ALU)

The ALU performs:

  • Arithmetic operations
  • Logical operations

Control Unit (CU)

The Control Unit controls and coordinates the activities of:

  • Memory
  • ALU
  • Input devices
  • Output devices

Cache Memory

Cache memory is a small, high-speed memory that improves CPU performance by providing faster access to frequently used data.


SRAM (STATIC RAM)

SRAM stores data using flip-flop circuits.

Characteristics

  • Faster than DRAM
  • Does not require refreshing
  • Highly stable
  • Commonly used in cache memory

OPERATING SYSTEM

Linux

Linux is an open-source operating system developed through community participation and collaborative development.

Characteristics

  • Open source
  • Widely used
  • Community driven

EMAIL FORWARDING

When the Forward option is selected in an email application, a new email draft opens containing the original email content, allowing it to be sent to another recipient.

Computer Fundamentals Computer Awareness Programming in C C++ Programming Java Programming Java Applets String Functions strlen() strcmp() strcpy() strcat() strchr() strrchr() strstr() strtok() Data Types Integer Data Type Primitive Data Types Non-Primitive Data Structures Arrays Linked List Stack Queue Tree Graph Data Structures Linked List Operations Traversal Insertion Deletion SQL Commands SQL Update Statement Database Management System DBMS Microsoft Access Computer Networks LAN MAN WAN Network Devices Gateway Router Switch Hub Bridge Repeater Modem Host Internet Concepts FTP File Transfer Protocol Email Address Structure Local Part and Domain Zip Drive Computer Hardware ALU Control Unit Cache Memory SRAM Operating System Linux Assembler Compiler Interpreter Object Oriented Programming Member Function Return Statement Goto Statement Switch Statement Address Operator Pointer Concepts File Handling in C fscanf() Concept Keyboard Point of Sale Systems MS Office MS Word MS Excel MS PowerPoint F2 Key F4 Key F5 Key TEXT Function Excel Formulas Sleep Mode Collate Printing Themes in PowerPoint Image Cropping Email Forwarding Computer Memory Programming Concepts Software Engineering Basics Information Technology Digital Literacy Computer MCQs Computer Notes RRB JE CBT 2 Computer RRB JE Computer Awareness SSC CGL Computer Awareness SSC CHSL Computer Awareness SSC JE Computer Science Railway Exams Computer Competitive Computer Notes Objective Computer Questions Government Exam Computer GK Technical Aptitude Computer Science Basics Computer Applications Information and Communication Technology ICT Digital Systems RRB JE NOTES RRB JE CBT 2 NOTES SSC JE NOTES COMPUTER AWARENESS NOTES COMPUTER FUNDAMENTALS NOTES TECHNICAL APTITUDE NOTES COMPETITIVE EXAM NOTES.
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