C-and-C++/C4/Working-With-Structures/English

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Title of script: Structures

Author: Ashwini Patil

Keywords: Strucutre, structure variable, Video tutorial.



Visual Cue
Narration


Slide 1 Welcome to the spoken-tutorial on Structures in C and C++.
Slide 2

Learning Objectives

In this tutorial we will learn what,

Is a Structure.

Declaration of a structure

We will do this through an example



Slide 3

System requirements

To record this tutorial, I am using,

Ubuntu Operating System version 11.04,

gcc and g++ Compiler version 4.6.1

Slide 4

Introduction

Let us start with the introduction to Structure

When one or more variables are grouped under one name it is known as structure.

Strucutre is used to group different data into one object.

It is called as compound data-type.

It is used to group related information together.

Slide 5 Now we will see

The syntax to declare a structure

Here the keyword struct tells the compiler that a structure is declared

strcut_name is the name of the structure.

eg. struct employee;

You can give any name.

Slide 6 Now we will see how to declare a structure variable.

The Syntax for this is

struct struct_name and struct_var;

struct_var is the variable of type struc_name

eg. struct employee addr;

addr is the variable of type employee.

Let us move on to our example
I have already typed the program on the editor

So let me open it.

Point to struct.c Note that our filename is structure.c
In this program we will calculate the total marks of three subjects using structure
Let me explain the code now.
Highlight

#include <stdio.h>

This is our header file.
Highlight

struct student

Here we have declared a structure as student.



Highlight

int eng;

int maths;

int science;

Then we have declared three integer variables as english, maths and science.

Variables defined under the structure are called as members of the structure.

Highlight

int main()

This is our main function
Highlight

int total

Here we have declared an integer variable total.
Highlight

struct student st;

Now we have declared a structure variable stud, stud is the variable of type student,it is used to access and modify the structure members



Highlight

st.eng = 75;

st.maths = 70;

st.science = 65;

Here we have modified the members

By assigning them values of 75, 70 and 65.

Highlight

total = st.eng + st.maths + st.science;

Here we calculate the total of the three subjects.
Highlight

printf("Total is %d\n",total);

Then we print the result.
Highlight

return 0;

This is our return statement.
Click on Save Now click on Save
Let us execute the program
Press Ctrl, Alt and T keys Please open the terminal window by pressing

Ctrl, Alt and T keys simultaneously on your keyboard.

Type

gcc struct.c -o struc


Type

./struc

To compile

Type

gcc space structure.c space -o space struct

And press Enter

To execute

Type

./struct

Press Enter

Highlight

Output

The output is displayed as:

Total is 210

In C++ Now we will execute the same program in C++
On the editor Come back to our program.
I will edit the same code
Click on Save as option

Type

.cpp

First press shift, cntrl and S keys simultaneously on the keyboard

Now save the file with an extension .cpp

and click on save

Type

iostream

Let us change the header file as iostream
Type

using namespace std;

Now include the using statement

and click on save

Structure declaration in C++ is same as in C

So no need to change anything here

Type

cout <<

At the end we will replace the printf statement with the cout << statement.
Delete \n and ,


Type

<<

<< “\n”

Delete the format specifier and \n

Now delete the comma

Type

two opening angle brackets.

Here delete the closing bracket

and type two opening angle backets

And within the double quotes type \n

Click on Save Now click on Save
Let us execute the program
On the terminal

Type

g++ struc.cpp -o st2

Type

./st2

Come back to our terminal

To compile type

g++ space structure.cpp space -o space struct1

Here we have struct1 because we dont want to overwrite the output parameters for the file structure.c

Now press Enter

To execute type

./struct1

Press Enter

Highlight

Output

The output is displayed as:

Total is 210

You can see that the output is same as our C code

Now come back to our slides.

Slide 7

Summary

We will summarize now. In this tutorial we learned,

Structure.

Syntax of a structure.

eg. struct struct_name;

To access members of a structure.

Eg: stud.maths = 75;

To add the structure variables.

Eg: total = stud.eng + stud.maths + stud.science;

Slide 8

Assignment

As an assignment,

Write a program to diplay the records of an employee.

Like name, address, designation and salary.

Slide 9

http://spoken-tutorial.org /What\_is\_a\_Spoken\_Tutorial

About the Spoken Tutorial Project

Watch the video available at the link shown below

It summarises the Spoken Tutorial project

If you do not have good bandwidth, you can download and watch it

Slide 10

Spoken Tutorial Workshops

The Spoken Tutorial Project Team

Conducts workshops using spoken tutorials

Gives certificates to those who pass an online test

For more details, please write to

contact@spoken-tutorial.org

Slide 11


Acknowledgement

Spoken Tutorial Project is a part of the Talk to a Teacher project

It is supported by the National Mission on Education through ICT, MHRD, Government of India

More information on this Mission is available at the link shown below: http://spoken-tutorial.org\NMEICT-Intro

Ashwini Patil from IIT Bombay

Thank You for joining

Contributors and Content Editors

Ashwini