C-and-C++/C3/Arrays/English

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Title of script: Arryas in C and C++

Author: Ashwini Patil

Keywords: arrays, single dimensional, multi dimensional, video tutorial()


Visual Cue
Narration
Slide 1 Welcome to the spoken-tutorial on Arrays in C and C++.
Slide 2 In this tutorial we will learn,

What is an array.

Declaration of an array.

Initialization of an array.

We will do this with the help of an example.

We will also explain some common errors and their solutions.

Slide 3 To record this tutorial, I am using,

Ubuntu Operating System version 11.04,

gcc and g++ Compiler version 4.6.1 on Ubuntu.

Slide 4-5 Let us start with the introduction to Array.

Array is the collection of data or elements of same data-type.

Array index starts from 0.

The first element is stored at index 0.

eg. pen[5];

Here, we are declaring a character array which contains 5 elements.

pen[0] to pen[4].

There are three types of arrays:

  1. Single dimensional array.
  2. Two dimensional array.
  3. Multi-dimensional array.

We will be discussing single dimensional array in this tutorial.

Slide 6 Let us see how to declare single dimensional array.

The Syntax for this is:

data-type array-name[size];

eg. char star[5];

Slide 7 Let us see how to initialize the array.

The Syntax for this is:

data-type array-name[size]={values};

eg. int star[3]={1,2,3};

On the editor Now let us see how to declare an array through an example.

I have already typed the program on the editor.

So, I will open it.

Let me explain the program.

Point to array.c Note that our file name is array.c
In this program, we will calculate the sum of the elements stored in an array.
Highlight

#include <stdio.h>

This is our header file.
Highlight

int main()

This is our main function.
Highlight

int star[3]={1,2,3};


Here, we have declared and initialized an array star with size 3.
Highlight

int sum;

Then we have declared a variable sum.
Highlight

sum = star[0] + star[1] + star[2];

Here we add the values and store the result in sum.
Highlight

printf("The sum is %d\n",sum);

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 the terminal

Type

gcc array.c -o arr

./arr

To compile type,

gcc array.c -o arr


To execute type,

./arr

Highlight

Output

Here the output is displayed as,

The sum is 6.

Errors Now let us see some common errors which we can come accross.
On the editor Come back to our program.
Delete {}

int star[3]=1,2,3;

Suppose here, we miss the curly brackets.
Click on Save Click on Save.
Let us execute.
On the terminal Come back to the terminal.

Let us compile as before.

Let us execute as before.

Highlight

Error

We see an error.

Invalid initializer and Expected identifier or '(' before numeric constant.

{ } As arrays must be initialized within curly brackets.
Now let us see how to execute the same program in C++.
On the editor Come back to our program.
I will change a few things here.
Click on File menu

Click on Save as option

First click on File menu,

Click on Save as option,

Save the file with .cpp extension.

Type

iostream

Let us change the header file as iostream.
Type

using namespace std;

Include the using statement.
Type

cout <<

Now replace the printf statement with the cout statement.
Click on Save click on Save
Lets execute the program.
On the terminal Come back to the terminal
Type

g++ array.cpp -o arr

Type

./arr

To compile type,

g++ array.cpp -o arr

To execute

./arr

Highlight

Output

Here the output is displayed as,

The sum is 6.

Errors Now let see another common error
At line 7

Type:

star[1] + star[2] + star[3];

Suppose here, at line number 7

We type star[1] + star[2] + star[3];

On the terminal Let us execute and see.

Come back to the terminal.

Let us compile and execute as before.
Highlight

Output

The output is displayed as:

The sum is ....

We get an unexected output.

This is because array index starts from 0.

Highlight

star[1]

Come back to the editor

Here the index starts from 1

Hence it is giving an error.

Summary In this tutorial we learned,

Arrays.

To declare Single Dimensional Array.

To initialize Single Dimensional Array.

eg. int star[3]={1,2,3}

Assignment As an assignment,

Write a program to calculate the difference of the elements stored in an array.

Slide 11

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 12

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 13


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: http://spoken-tutorial.org\NMEICT-Intro

Ashwini Patil from IIT Bombay

Thank You for joining

Contributors and Content Editors

Ashwini