Nancyvarkey: Created page with "{| border=1 ||'''Time''' || '''Narration''' |- | 00:02 | Welcome to the spoken tutorial on '''First C++ program'''. |- | 00:07 | In this tutorial I am going to explain, |..."

2015-04-10T09:22:54Z

Created page with "{| border=1 ||'''Time''' || '''Narration''' |- | 00:02 | Welcome to the spoken tutorial on '''First C++ program'''. |- | 00:07 | In this tutorial I am going to explain, |..."

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{| border=1
||'''Time'''
|| '''Narration'''
|-
| 00:02
| Welcome to the spoken tutorial on '''First C++ program'''.

|-
| 00:07
| In this tutorial I am going to explain,

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| 00:10
| *How to write a C++ program

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| 00:13
| *How to compile it

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| 00:14
| *How to execute it

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| 00:17
| We will also explain some common errors and their solution.

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| 00:22
| To record this tutorial, I am using Ubuntu operating system version 11.10 and

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| 00:29
| G++ Compiler version 4.5.2 on Ubuntu.

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| 00:35
| To practice this tutorial,

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| 00:37
| You should be familiar with Ubuntu Operating System and an Editor

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| 00:44
|Some editors are 'vim' and 'gedit'.

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| 00:48
| I am using 'gedit' in this tutorial.

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| 00:50
| For relevant tutorial please visit our website which is as shown.

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| 00:56
| Let me tell you how to write a C++ program through an example.

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| 01:01
| Open the terminal Window using '''Ctrl, Alt and T keys''' simultaneously on your keyboard.

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| 01:09
| To open the text editor, type on the terminal.

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| 01:13
| '''“gedit”''' space '''“talk”''' dot '''“.cpp”''' space ampersand '''“&”''' sign.

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| 01:21
| We use the '''“&”''' to free up the prompt.

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| 01:25
| Please note that all the C++ files will have the extension '''“.cpp”'''.

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| 01:31
| Now Press '''Enter''',

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| 01:33
|the text editor has opened.

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| 01:35
| Let us start to write a program.

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| 01:38
| Type double slash '''“//”''' space '''“My first C++ program”.'''

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| 01:44
| Here, double slash is used to comment the line.

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| 01:49
| Comments are used to understand the flow of program.

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| 01:52
| It is useful for documentation.

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| 01:55
| It gives us information about the program.

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| 01:59
| The double slash is called as single line comment. Now press Enter.

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| 02:05
| Type (hash) '''“#include”''', space, opening angle bracket, closing angle bracket .

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| 02:13
|It is a good practice to complete the brackets first, and then start writing inside it.

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| 02:20
| Now Inside the bracket, type '''“iostream”''' .

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| 02:23
| Here '''iostream''' is a '''header file'''.

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| 02:26
| This file includes the declaration of standard input output functions in '''C++.''' Now press '''Enter'''.

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| 02:35
| Type '''“using”''' space '''“namespace”''' space '''“std”''' and a semicolon '''“;”''' .

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|02:45
| The '''using''' statement informs the compiler that you want to use the '''std namespace'''.

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| 02:52
| The purpose of '''namespace''' is to avoid name collisions.

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| 02:56
| It is done by localizing the names of identifiers.

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|03:00
| It creates a declarative region and defines a scope.

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| 03:05
| Anything defined within a '''namespace''' is in the SCOPE of that namespace.

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| 03:11
|Here '''std''' is the '''namespace''' in which entire standard C++ library is declared. Now press '''Enter'''.

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| 03:20
| Type '''“int”''' space '''“main”''' opening bracket, closing bracket .

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| 03:26
| '''main''' is a special '''function'''.

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| 03:30
| It denotes that the execution of the program begins from this line.

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| 03:34
|The opening and the closing bracket is called as'' Parenthesis''.
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| 03:39
| Parenthesis followed by '''main''' tells the user that '''main''' is a '''function.'''

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| 03:45
| Here, the '''int''' '''main()''' function takes no '''arguments''' and returns a value of type integer.

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| 03:52
| We will learn about data types in another tutorial.

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| 03:56
|Now let us switch to the slides to know more about main function.

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| 04:02
| Every '''program''' should have one main function.

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| 04:04
| There should NOT be more than one “main” function.

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| 04:09
| Otherwise the compiler cannot locate the beginning of the program.

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| 04:13
| The empty pair of parentheses indicates that main has no '''arguments'''.

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| 04:19
| The concept of '''arguments''' will be discussed in the upcoming tutorials.

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| 04:24
| Now come back to our program. Press Enter.

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| 04:29
| Type opening curly bracket '''“{”'''.

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| 04:32
| The opening curly bracket marks the beginning of the function '''main()'''.

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| 04:37
|Then Type closing curly bracket '''“}”'''.

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| 04:40
| The closing bracket indicates the end of the function '''main()'''.

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| 04:45
|Now, inside the bracket press enter twice.

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| 04:49
| Move the cursor one line up.

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|04:51
| Indentation makes the code easier to read.

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| 04:54
| It also helps to locate errors faster.

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| 04:58
|So let us give a space here.

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| 05:01
|And type '''“cout”''' space two opening angle bracket ''''.

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| 05:07
| Here '''cout '''is a standard '''C++ function''' to print the output on the terminal.

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| 05:14
|Now after the brackets, type within double quotes.

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| 05:18
|Anything within the double quotes, in the '''cout ''' functions, will be printed.

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| 05:24
|Now inside a quote type“Talk to a teacher backslash n” (\n)'''.

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| 05:31
| Here '''\n''' signifies newline.

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| 05:35
| As a result, after execution of the '''cout''' function, the cursor moves to the new line.

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| 05:41
| Every C++ statement must end with a '''semicolon'''.

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| 05:45
| Hence type it at the end of this line.

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| 05:48
| Semicolon acts as a statement terminator. Now press '''Enter.'''

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| 05:53
| Give a space here and Type '''“return”''' space '''“0”''' and a semicolon '''“;”.'''

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| 06:00
| This statement returns the integer zero.

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| 06:03
| An integer has to be returned for this '''function''' because the '''function''' type is '''int'''.

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| 06:10
| The '''return''' statement marks the end of executable statements.

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| 06:14
| We will learn more about the returned values in another tutorial.

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| 06:20
| Now click on '''“Save”''' button to save the file.

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| 06:23
| It is a good habit to save files frequently.

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| 06:26
| This will protect you from sudden power failures.

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| 06:30
| It will also be useful in case the applications were to crash.

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| 06:34
| Let us now compile the program.

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| 06:36
| Come back to our terminal.

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| 06:39
| Type '''“g++”''' space '''“talk.cpp”''' space hyphen '''“-o”''' space '''“output”.'''

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| 06:49
|Here '''g++''' is the compiler used to compile '''C++ '''programs.

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| 06:55
| '''talk.cpp''' is our filename.

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| 06:59
| '''hyphen -o output''' says that the executable should go to the file "output".

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| 07:05
| Now press '''Enter'''.

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| 07:07
| We see that the program is compiled.

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| 07:10
| By typing '''ls space hyphen lrt''', we can see that '''output''' is the last file to be created.

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| 07:19
| Let us execute a program, type '''“./output” '''(dot slash output).

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| 07:24
|And Press '''Enter.'''

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| 07:27
| Here the output is displayed as '''“Talk to a teacher”.'''

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| 07:30
| Now let us see the common errors which we can come across.

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| 07:35
| Switch back to our text editor.

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| 07:38
| Suppose here we miss the '''}'''(closing curly bracket)
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| 07:42
|now save the file.

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| 07:44
| Let us execute. Come back to our terminal.

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| 07:48
| Now compile and run the program using the command we used before. We see an error.

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| 07:55
| We see that there is an error at line no.7 in our '''talk.cpp''' file that "expected curly bracket at the end of input".

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| 08:07
|Now Come back to our text editor .

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| 08:09
| As I said before, the closing curly bracket marks the end of the function main

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| 08:14
| Hence re-insert the bracket here. Now Save the file.

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| 08:19
| Let us execute it again.

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| 08:21
| You can recall the previously entered commands by using up arrow key.

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| 08:26
| That is what I did now.

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| 08:30
| Yes, it is working.

|-
|08:32
| I will show you another common error.

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| 08:35
| Let us switch back to our text editor.

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| 08:37
| Now, suppose here we missed '''std.'''

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| 08:41
| Let us save the file.

|-
| 08:44
| Come back to our terminal .

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| 08:46
| Let us compile .

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| 08:48
| We see that there is an error at line no.3 and line no.6 in our '''talk.cpp''' file.

|-
| 08:56
| That "expected identifier before 'semicolon' " and " 'cout' was not declared in this scope".

|-
|09:05
| As '''cout''' is the standard '''C++ library function'''.

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| 09:09
| and the entire '''C++ library function''' is defined under '''std namespace '''.

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| 09:15
| Hence it is giving an error.

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| 09:18
| Let us now fix the error.

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| 09:19
| Come back to our Text editor. Type '''std''' here.

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| 09:23
| Let us save it.

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| 09:25
| Let us compile it again.

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| 09:29
| Yes, it is working.

|-
| 09:32
| As an assignment,

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| 09:33
| write a program to print your name and city.

|-
| 09:37
| We used '''single line comment''' in this tutorial.

|-
|09:40
| Now just try to give a '''multiline comment'''.

|-
| 09:44
| Watch the video available at the link shown below.

|-
| 09:46
| It summarizes the Spoken Tutorial project.

|-
| 09:48
| If you do not have good bandwidth, you can download and watch it.

|-
|09:53
|The Spoken Tutorial Project Team:

|-
| 09:55
| Conducts workshops using spoken tutorials.

|-
|09:58
| Gives certificates to those who pass an online test.

|-
| 10:01
| For more details, please write to contact @spoken-tutorial.org

|-
|10:10
| Spoken Tutorial Project is a part of the Talk to a Teacher project.

|-
| 10:14
| It is supported by the National Mission on Education through ICT, MHRD, Government of India.

|-
| 10:20
| More information on this Mission is available at the link shown below.

|-
| 10:25
| This is Jean Bonnet from IIT Bombay signing off.

|-
| 10:28
| Thank you for watching.

|}

C-and-Cpp/C2/First-Cpp-Program/English-USA - Revision history

Nancyvarkey: Created page with "{| border=1 ||'''Time''' || '''Narration''' |- | 00:02 | Welcome to the spoken tutorial on '''First C++ program'''. |- | 00:07 | In this tutorial I am going to explain, |..."