Skip to main content

Arrays of C Program

Arrays in C programming starts with memory addresses. Yes the compiler handles arrays as memory addresses.
  • Similar elements group together with a single name is called array
  • the indexing always starts with 0 and ends at n-1 (if the size of the array is n)
  • Array elements stores in consecutive memory location.
The array elements usually stores in consecutive memory location. For example,
int a[10];  //Array with size 10
the above example is an integer array with size 10 or this array can hold 10 variables.
The elements starts from a[0], a[1], a[2]…..a[9], so totally there are 10 elements.
Array elements values memory address location
a[0] 32 600AH  (This address is called as the base address)
a[1] 34 600EH
a[2] 23 6012H
a[3] 35 6016H
a[4] 45 601AH
a[5] 67 601EH
a[6] 56 6022H
a[7] 1 6026H
a[8] 34 602AH
a[9] 25 602EH
The memory addresses shown above are in hexadecimal, that’s why each address suffixed with a letter H. The memory addresses in each machine will be different.
The base address is the address where the first element of the array is stored. Usually it is represented as &a[0] or simply a.
The entire array is represented as an address by specifying the base address alone to various other elements of C programming like passing array to functions involves sending the base address only.
For the above table, here is the declaration syntax
int a[10]={32,34,23,35,45,67,56,1,34,25};
or
int a[]={32,34,23,35,45,67,56,1,34,25};
A simple program to get some numbers and print them on the screen
int main()
{
int a[10], j; //declaration of array “a” and its index j
printf(“Enter all the 10 numbers”);
for(j=0;j<10;j++) //get the numbers using a for loop which executes for 10 times (0 to 9)
{
scanf(“%d”, &a[j]);
}
for(j=0;j<10;j++) //print the numbers using a for loop which executes for 10 times (0 to 9)
{
printf(“%d”,a[j]);
}
return 0;
}
In the above example, j varies from 0 to 9 which means the loop will execute 10 times for the array a like this
a[j] when j=0 then a[0]
a[j] when j=1 then a[1]
a[j] when j=2 then a[2]…. and so on
like this the input is entered through the keyboard and same for printing the output.

 T S Pradeep Kumar

Comments

Popular posts from this blog

Routing in VANETs using ns3

Part 1
WAVE - Wireless Access for Vehicular environments. vanet-routing-compare.cc It might take more than an hour. The readers are requested to be patient. SUMO, VANETs, routing comparison 1. Explain the full source code (1550 lines of code) 2. Creating a real scenario using osm (Open Street Map Web Wizard) 3. Performance analysis for various vanet protocols. https://www.nsnam.com Location of the source code /home/pradeepkumar/ns-allinone-3.27/ns-3.27/src/wave/examples
Move this file to the scratch/ for inclusion of all modules. Step 1: Explanation of source code. Copy the file to scratch folder. This is just Part 1 of the VANET comparison

Part 2 Please watch the First Part before watching this video   https://www.youtube.com/watch?v=IJYeIpUqjQI&t=850s
Part 2 - Analysis of the results.
Please go through the first video (Part 1) and then watch this video (PArt 2)
#VANETs #NS3 #Routing
1. SUMO for web traffic (osmWebWizard.py) 2. Convert this into mobility.tcl file and t…

ns3 installation in Ubuntu 16.04

This post serves the installation instructions of ns3 in ubuntu 16.04 version. Some of my students are working in ns3, this post will benefit them in installing ns3.

OS Used: Ubuntu 16.04.4
ns3 version: ns3 version 3.27

The same procedure will be applied for OS like Debian, Linux Mint.

Fresh installation of Ubuntu 16.04 Let you try the fresh installation of ubuntu in your hard disk along with windows.
Installation of ns3 dependencies ns3 needs so many dependencies, developmental libraries, drivers, etc. so install all those
$] sudo apt update  $] sudo apt upgrade
$] sudo apt-get install build-essential autoconf automake libxmu-dev python-pygoocanvas python-pygraphviz cvs mercurial bzr git cmake p7zip-full python-matplotlib python-tk python-dev python-kiwi python-gnome2 python-gnome2-desktop-dev python-rsvg qt4-dev-tools qt4-qmake qt4-qmake qt4-default gnuplot-x11 wireshark
The above command make take some time to download, compile and install it, Be Patient. 
Installing ns3 Download the…

TORA Protocol in NS-2.35 (NS2)

This post tells you how to enable the TORA (Temporally ordered routing Algorithm) protocol in Network Simulator 2 (ns-2.35)

TORA is a protocol in wireless adhoc networks that works with timing parameters. NS-2.35 comes with the TORA protocol by default but it has to be tweaked manually to make it run.
This post will help you to do that.

You can watch this video for detailed instructions:


Step 1: Generate a Scenario for TORA protoco using NS2 Scenario Generator NSG Software.
We have created a tcl file using NSG2.1.jar

$] java -jar NSG2.1.jar

Three files have to be modified
~ns-2.35/tora/tora.cc~ns-2.35/tora/tora.h~ns-2.35/imep/imep.cc There are various websites that tells you how to configure TORA by making changes to the above three files.  Change 1: tora.h In the tora.h file, go to the end of the File before the agent completes, include these two lines

#include <classifier/classifier-port.h>
protected: PortClassifier *dmux_;

Change 2: tora.cc Open the tora.cc and include the follow…