Difference between revisions of "C-and-C++/C4/Understanding-Pointers/English-timed"
From Script | Spoken-Tutorial
PoojaMoolya (Talk | contribs) |
|||
(4 intermediate revisions by 2 users not shown) | |||
Line 1: | Line 1: | ||
{| border = 1 | {| border = 1 | ||
− | + | |'''Time''' | |
− | |Time | + | |'''Narration''' |
− | |Narration | + | |
− | + | ||
|- | |- | ||
| 00:01 | | 00:01 | ||
− | |Welcome to the spoken tutorial on '''Pointers in C and C++ ''' | + | |Welcome to the spoken tutorial on '''Pointers in C and C++ '''. |
|- | |- | ||
| 00:06 | | 00:06 | ||
− | |In this tutorial we will learn | + | |In this tutorial we will learn: |
|- | |- | ||
| 00:08 | | 00:08 | ||
− | |Pointers | + | |Pointers |
|- | |- | ||
| 00:10 | | 00:10 | ||
− | |To create Pointers | + | |To create Pointers |
|- | |- | ||
Line 27: | Line 25: | ||
|- | |- | ||
| 00:14 | | 00:14 | ||
− | | We will do this with the help of an example | + | | We will do this with the help of an example. |
|- | |- | ||
| 00:18 | | 00:18 | ||
− | |To record this tutorial I am using Ubuntu operating system version 11.10 | + | |To record this tutorial, I am using '''Ubuntu operating system''' version 11.10, |
|- | |- | ||
| 00:25 | | 00:25 | ||
− | | gcc and g++ compiler version 4.6.1 on Ubuntu | + | | '''gcc and g++ compiler''' version 4.6.1 on Ubuntu. |
|- | |- | ||
| 00:31 | | 00:31 | ||
− | |Let us start with an introduction to pointers | + | |Let us start with an introduction to pointers. |
|- | |- | ||
Line 55: | Line 53: | ||
|- | |- | ||
| 00:45 | | 00:45 | ||
− | |Now, let us see an example on pointers | + | |Now, let us see an example on pointers. |
|- | |- | ||
| 00:48 | | 00:48 | ||
− | |Note that our file name is '''pointers_demo.c''' | + | |Note that our file name is '''pointers_demo.c'''. |
|- | |- | ||
| 00:54 | | 00:54 | ||
− | |Let us go through the code now | + | |Let us go through the code now. |
|- | |- | ||
| 00:56 | | 00:56 | ||
− | |This is our header file as '''stdio.h''' | + | |This is our header file as '''stdio.h'''. |
|- | |- | ||
| 01:00 | | 01:00 | ||
− | |This is our main function | + | |This is our '''main()''' function. |
|- | |- | ||
| 01:03 | | 01:03 | ||
− | |Here we have '''long integer num''' assigned value '''10.''' | + | |Here we have '''long integer num''', assigned value '''10.''' |
|- | |- | ||
| 01:09 | | 01:09 | ||
− | |Then we have declared a pointer ptr. | + | |Then we have declared a pointer '''ptr'''. |
|- | |- | ||
Line 91: | Line 89: | ||
|- | |- | ||
| 01:20 | | 01:20 | ||
− | |In the printf statement ampersand is used for retrieving memory address of the variable. | + | |In the 'printf' statement, ampersand is used for retrieving memory address of the variable. |
|- | |- | ||
|01:28 | |01:28 | ||
− | |So ampersand num will give the memory address of num. | + | |So, ampersand num (&num) will give the memory address of '''num'''. |
|- | |- | ||
Line 103: | Line 101: | ||
|- | |- | ||
| 01:37 | | 01:37 | ||
− | |Over here ptr stores the address of num. | + | |Over here, ptr stores the address of num. |
|- | |- | ||
| 01:41 | | 01:41 | ||
|This statement will print the address of ptr. | |This statement will print the address of ptr. | ||
− | |||
|- | |- | ||
| 01:45 | | 01:45 | ||
− | | | + | |'''sizeof()''' function will give the size of ptr. |
|- | |- | ||
Line 128: | Line 125: | ||
|- | |- | ||
|01:59 | |01:59 | ||
− | |So using asterisk will not give the memory address. | + | |So, using asterisk will not give the memory address. |
|- | |- | ||
Line 136: | Line 133: | ||
|- | |- | ||
|02:06 | |02:06 | ||
− | |%ld is a format specifier for the long int | + | |'''%ld''' is a format specifier for the '''long int'''. |
|- | |- | ||
|02:10 | |02:10 | ||
− | |Now, let us execute the program | + | |Now, let us execute the program. |
|- | |- | ||
|02:13 | |02:13 | ||
− | |Open the terminal window by pressing Ctrl, Alt and T keys simultaneously on your keyboard | + | |Open the terminal window by pressing '''Ctrl, Alt''' and '''T''' keys simultaneously on your keyboard. |
|- | |- | ||
|02:21 | |02:21 | ||
− | |To compile type '''gcc space pointers underscore demo dot c space hyphen o space point''' | + | |To compile, type '''gcc space pointers underscore demo dot c space hyphen o space point''' |
− | + | ||
|- | |- | ||
|02:32 | |02:32 | ||
− | |Press '''Enter''' | + | |Press '''Enter'''. |
|- | |- | ||
|02:34 | |02:34 | ||
− | |Type '''dot slash point'''. Press '''Enter''' | + | |Type '''dot slash point'''. Press '''Enter'''. |
|- | |- | ||
|02:39 | |02:39 | ||
− | |The output is displayed | + | |The output is displayed. |
|- | |- | ||
| 02:42 | | 02:42 | ||
− | |We see that the num address and ptr value is same | + | |We see that the num address and ptr value is same |
|- | |- | ||
| 02:48 | | 02:48 | ||
− | | | + | | where as memory address of num and ptr are different. |
|- | |- | ||
Line 185: | Line 181: | ||
|- | |- | ||
| 03:07 | | 03:07 | ||
− | | Note that our file name is '''pointer underscore demo.cpp''' | + | | Note that our file name is '''pointer underscore demo.cpp'''. |
|- | |- | ||
| 03:13 | | 03:13 | ||
− | | Here we have few changes like the header file as '''iostream''' | + | | Here we have a few changes like the header file as '''iostream'''. |
|- | |- | ||
| 03:19 | | 03:19 | ||
− | |Then we are using the '''std namespace''' | + | |Then we are using the '''std namespace'''. |
|- | |- | ||
| 03:23 | | 03:23 | ||
− | |And we have the cout function in place of printf function | + | |And here we have the '''cout''' function in place of printf() function. |
|- | |- | ||
| 03:28 | | 03:28 | ||
− | |Rest all the things are similar | + | |Rest all the things are similar. |
|- | |- | ||
Line 209: | Line 205: | ||
|- | |- | ||
| 03:34 | | 03:34 | ||
− | |To compile type '''g++ space pointers_demo.cpp space hyphen o space point1''', press Enter | + | |To compile, type '''g++ space pointers_demo.cpp space hyphen o space point1''', press Enter. |
|- | |- | ||
| 03:50 | | 03:50 | ||
− | |Type '''dot slash point1''', press '''Enter''' | + | |Type '''dot slash point1''', press '''Enter'''. |
|- | |- | ||
| 03:55 | | 03:55 | ||
− | | We can see that the output is similar to our C program | + | | We can see that the output is similar to our C program. |
|- | |- | ||
Line 225: | Line 221: | ||
|- | |- | ||
| 04:03 | | 04:03 | ||
− | | Come back to our slide | + | | Come back to our slide. |
|- | |- | ||
| 04:05 | | 04:05 | ||
− | |Let us summarize | + | |Let us summarize.In this tutorial, we learnt: |
− | + | ||
− | + | ||
− | + | ||
− | + | ||
|- | |- | ||
Line 249: | Line 241: | ||
|- | |- | ||
| 04:14 | | 04:14 | ||
− | |As an assignment, write a C and C++ program | + | |As an assignment, write a C and C++ program |
|- | |- | ||
| 04:18 | | 04:18 | ||
− | | | + | |to declare a variable and pointer. |
|- | |- | ||
Line 265: | Line 257: | ||
|- | |- | ||
| 04:27 | | 04:27 | ||
− | |Watch the video available at the link shown below | + | |Watch the video available at the link shown below. |
|- | |- | ||
| 04:30 | | 04:30 | ||
− | |It summarizes the Spoken Tutorial project | + | |It summarizes the Spoken Tutorial project. |
|- | |- | ||
| 04:33 | | 04:33 | ||
− | |If you do not have good bandwidth, you can download and watch it | + | |If you do not have good bandwidth, you can download and watch it. |
|- | |- | ||
| 04:37 | | 04:37 | ||
− | |The Spoken Tutorial Project Team | + | |The Spoken Tutorial Project Team: |
|- | |- | ||
| 04:39 | | 04:39 | ||
− | |Conducts workshops using spoken tutorials | + | |Conducts workshops using spoken tutorials. |
|- | |- | ||
|04:43 | |04:43 | ||
− | |Gives certificates to those who pass an online test | + | |Gives certificates to those who pass an online test. |
|- | |- | ||
| 04:47 | | 04:47 | ||
− | |For more details, please write to | + | |For more details, please write to contact@spoken-tutorial.org. |
|- | |- | ||
| 04:53 | | 04:53 | ||
− | |Spoken Tutorial Project is a part of the Talk to a Teacher project | + | |Spoken Tutorial Project is a part of the Talk to a Teacher project. |
|- | |- | ||
| 04:58 | | 04:58 | ||
− | |It is supported by the National Mission on Education through ICT, MHRD, Government of India | + | |It is supported by the National Mission on Education through ICT, MHRD, Government of India. |
|- | |- | ||
| 05:06 | | 05:06 | ||
− | |More information on this | + | |More information on this mission is available at the link shown below. |
|- | |- | ||
| 05:10 | | 05:10 | ||
− | | This is Ashwini Patil from IIT Bombay signing off | + | | This is Ashwini Patil from IIT Bombay, signing off. |
|- | |- | ||
| 05:14 | | 05:14 | ||
|Thank You for joining. | |Thank You for joining. |
Latest revision as of 14:53, 24 March 2017
Time | Narration |
00:01 | Welcome to the spoken tutorial on Pointers in C and C++ . |
00:06 | In this tutorial we will learn: |
00:08 | Pointers |
00:10 | To create Pointers |
00:12 | And operations on Pointers. |
00:14 | We will do this with the help of an example. |
00:18 | To record this tutorial, I am using Ubuntu operating system version 11.10, |
00:25 | gcc and g++ compiler version 4.6.1 on Ubuntu. |
00:31 | Let us start with an introduction to pointers. |
00:34 | Pointers point to the locations in memory. |
00.38 | Pointers store the memory address. |
00:41 | It also gives value stored at that address. |
00:45 | Now, let us see an example on pointers. |
00:48 | Note that our file name is pointers_demo.c. |
00:54 | Let us go through the code now. |
00:56 | This is our header file as stdio.h. |
01:00 | This is our main() function. |
01:03 | Here we have long integer num, assigned value 10. |
01:09 | Then we have declared a pointer ptr. |
01:12 | Asterisk sign is used to declare a pointer. |
01:16 | This pointer can point to type long int. |
01:20 | In the 'printf' statement, ampersand is used for retrieving memory address of the variable. |
01:28 | So, ampersand num (&num) will give the memory address of num. |
01:33 | This statement will print the address of the variable num. |
01:37 | Over here, ptr stores the address of num. |
01:41 | This statement will print the address of ptr. |
01:45 | sizeof() function will give the size of ptr. |
01:49 | This is will give the value of ptr. |
01:51 | That is the memory address of num. |
01:54 | And here asterisk ptr will give the value at the address. |
01:59 | So, using asterisk will not give the memory address. |
02:03 | Instead it will give the value. |
02:06 | %ld is a format specifier for the long int. |
02:10 | Now, let us execute the program. |
02:13 | Open the terminal window by pressing Ctrl, Alt and T keys simultaneously on your keyboard. |
02:21 | To compile, type gcc space pointers underscore demo dot c space hyphen o space point |
02:32 | Press Enter. |
02:34 | Type dot slash point. Press Enter. |
02:39 | The output is displayed. |
02:42 | We see that the num address and ptr value is same |
02:48 | where as memory address of num and ptr are different. |
02:53 | Then the size of pointer is 8 bytes. |
02:57 | Also the value pointed by ptr is 10 which was assigned to num. |
03:03 | Now let us see the same program in C++. |
03:07 | Note that our file name is pointer underscore demo.cpp. |
03:13 | Here we have a few changes like the header file as iostream. |
03:19 | Then we are using the std namespace. |
03:23 | And here we have the cout function in place of printf() function. |
03:28 | Rest all the things are similar. |
03:30 | Let us execute the program. Come back to our terminal. |
03:34 | To compile, type g++ space pointers_demo.cpp space hyphen o space point1, press Enter. |
03:50 | Type dot slash point1, press Enter. |
03:55 | We can see that the output is similar to our C program. |
04:00 | This brings us to the end of this tutorial. |
04:03 | Come back to our slide. |
04:05 | Let us summarize.In this tutorial, we learnt: |
04:08 | About the pointer. |
04:10 | To create a pointer. |
04:12 | And operation on pointer. |
04:14 | As an assignment, write a C and C++ program |
04:18 | to declare a variable and pointer. |
04:21 | Store the address of variable in the pointer. |
04:24 | And print the value of the pointer. |
04:27 | Watch the video available at the link shown below. |
04:30 | It summarizes the Spoken Tutorial project. |
04:33 | If you do not have good bandwidth, you can download and watch it. |
04:37 | The Spoken Tutorial Project Team: |
04:39 | Conducts workshops using spoken tutorials. |
04:43 | Gives certificates to those who pass an online test. |
04:47 | For more details, please write to contact@spoken-tutorial.org. |
04:53 | Spoken Tutorial Project is a part of the Talk to a Teacher project. |
04:58 | It is supported by the National Mission on Education through ICT, MHRD, Government of India. |
05:06 | More information on this mission is available at the link shown below. |
05:10 | This is Ashwini Patil from IIT Bombay, signing off. |
05:14 | Thank You for joining. |
Contributors and Content Editors
Kavita salve, Krupali, PoojaMoolya, Pratik kamble, Sandhya.np14, Sneha