Difference between revisions of "C-and-C++/C4/Understanding-Pointers/English-timed"
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− | | | + | |Time |
− | + | |Narration | |
− | | | + | |
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− | | 00 | + | | 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 | + | | 00:06 |
|In this tutorial we will learn, | |In this tutorial we will learn, | ||
|- | |- | ||
− | | 00 | + | | 00:08 |
|Pointers. | |Pointers. | ||
|- | |- | ||
− | | 00 | + | | 00:10 |
|To create Pointers. | |To create Pointers. | ||
|- | |- | ||
− | | 00 | + | | 00:12 |
|And operations on Pointers. | |And operations on Pointers. | ||
|- | |- | ||
− | | 00 | + | | 00:14 |
| We will do this with the help of an example | | We will do this with the help of an example | ||
|- | |- | ||
− | | 00 | + | | 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 | + | | 00:25 |
| gcc and g++ compiler version 4.6.1 on Ubuntu | | gcc and g++ compiler version 4.6.1 on Ubuntu | ||
|- | |- | ||
− | | 00 | + | | 00:31 |
|Let us start with an introduction to pointers | |Let us start with an introduction to pointers | ||
|- | |- | ||
− | |00 | + | |00:34 |
|Pointers point to the locations in memory. | |Pointers point to the locations in memory. | ||
Line 51: | Line 50: | ||
|- | |- | ||
− | | 00 | + | | 00:41 |
|It also gives value stored at that address. | |It also gives value stored at that address. | ||
|- | |- | ||
− | | 00 | + | | 00:45 |
|Now, let us see an example on pointers | |Now, let us see an example on pointers | ||
|- | |- | ||
− | | 00 | + | | 00:48 |
|Note that our file name is '''pointers_demo.c''' | |Note that our file name is '''pointers_demo.c''' | ||
|- | |- | ||
− | | 00 | + | | 00:54 |
|Let us go through the code now | |Let us go through the code now | ||
|- | |- | ||
− | | 00 | + | | 00:56 |
|This is our header file as '''stdio.h''' | |This is our header file as '''stdio.h''' | ||
|- | |- | ||
− | | 01 | + | | 01:00 |
|This is our main function | |This is our main function | ||
|- | |- | ||
− | | 01 | + | | 01:03 |
|Here we have '''long integer num''' assigned value '''10.''' | |Here we have '''long integer num''' assigned value '''10.''' | ||
|- | |- | ||
− | | 01 | + | | 01:09 |
|Then we have declared a pointer ptr. | |Then we have declared a pointer ptr. | ||
|- | |- | ||
− | | 01 | + | | 01:12 |
|Asterisk sign is used to declare a pointer. | |Asterisk sign is used to declare a pointer. | ||
|- | |- | ||
− | | 01 | + | | 01:16 |
|This pointer can point to type '''long int. ''' | |This pointer can point to type '''long int. ''' | ||
|- | |- | ||
− | | 01 | + | | 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 | + | |01:28 |
|So ampersand num will give the memory address of num. | |So ampersand num will give the memory address of num. | ||
|- | |- | ||
− | | 01 | + | | 01:33 |
|This statement will print the address of the variable num. | |This statement will print the address of the variable num. | ||
|- | |- | ||
− | | 01 | + | | 01:37 |
|Over here ptr stores the address of num. | |Over here ptr stores the address of num. | ||
|- | |- | ||
− | | 01 | + | | 01:41 |
|This statement will print the address of ptr. | |This statement will print the address of ptr. | ||
|- | |- | ||
− | | 01 | + | | 01:45 |
|Sizeof function will give the size of ptr. | |Sizeof function will give the size of ptr. | ||
|- | |- | ||
− | |01 | + | |01:49 |
|This is will give the value of ptr. | |This is will give the value of ptr. | ||
|- | |- | ||
− | |01 | + | |01:51 |
|That is the memory address of num. | |That is the memory address of num. | ||
|- | |- | ||
− | |01 | + | |01:54 |
|And here asterisk ptr will give the value at the address. | |And here asterisk ptr will give the value at the address. | ||
|- | |- | ||
− | |01 | + | |01:59 |
|So using asterisk will not give the memory address. | |So using asterisk will not give the memory address. | ||
|- | |- | ||
− | |02 | + | |02:03 |
|Instead it will give the value. | |Instead it will give the value. | ||
|- | |- | ||
− | |02 | + | |02:06 |
|%ld is a format specifier for the long int | |%ld is a format specifier for the long int | ||
|- | |- | ||
− | |02 | + | |02:10 |
|Now, let us execute the program | |Now, let us execute the program | ||
|- | |- | ||
− | |02 | + | |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 | + | |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 | + | |02:32 |
|Press '''Enter''' | |Press '''Enter''' | ||
|- | |- | ||
− | |02 | + | |02:34 |
|Type '''dot slash point'''. Press '''Enter''' | |Type '''dot slash point'''. Press '''Enter''' | ||
|- | |- | ||
− | |02 | + | |02:39 |
|The output is displayed | |The output is displayed | ||
|- | |- | ||
− | | 02 | + | | 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 | + | | 02:48 |
| Where as memory address of num and ptr are different. | | Where as memory address of num and ptr are different. | ||
|- | |- | ||
− | | 02 | + | | 02:53 |
|Then the size of pointer is '''8 bytes.''' | |Then the size of pointer is '''8 bytes.''' | ||
|- | |- | ||
− | | 02 | + | | 02:57 |
| Also the value pointed by '''ptr''' is 10 which was assigned to '''num.''' | | Also the value pointed by '''ptr''' is 10 which was assigned to '''num.''' | ||
|- | |- | ||
− | | 03 | + | | 03:03 |
| Now let us see the same program in C++. | | Now let us see the same program in C++. | ||
|- | |- | ||
− | | 03 | + | | 03:07 |
| Note that our file name is '''pointer underscore demo.cpp''' | | Note that our file name is '''pointer underscore demo.cpp''' | ||
|- | |- | ||
− | | 03 | + | | 03:13 |
| Here we have few changes like the header file as '''iostream''' | | Here we have few changes like the header file as '''iostream''' | ||
|- | |- | ||
− | | 03 | + | | 03:19 |
|Then we are using the '''std namespace''' | |Then we are using the '''std namespace''' | ||
|- | |- | ||
− | | 03 | + | | 03:23 |
|And we have the cout function in place of printf function | |And we have the cout function in place of printf function | ||
|- | |- | ||
− | | 03 | + | | 03:28 |
|Rest all the things are similar | |Rest all the things are similar | ||
|- | |- | ||
− | | 03 | + | | 03:30 |
|Let us execute the program. Come back to our terminal. | |Let us execute the program. Come back to our terminal. | ||
|- | |- | ||
− | | 03 | + | | 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 | + | | 03:50 |
|Type '''dot slash point1''', press '''Enter''' | |Type '''dot slash point1''', press '''Enter''' | ||
|- | |- | ||
− | | 03 | + | | 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 | ||
|- | |- | ||
− | | 04 | + | | 04:00 |
|This brings us to the end of this tutorial. | |This brings us to the end of this tutorial. | ||
|- | |- | ||
− | | 04 | + | | 04:03 |
| Come back to our slide | | Come back to our slide | ||
|- | |- | ||
− | | 04 | + | | 04:05 |
|Let us summarize | |Let us summarize | ||
|- | |- | ||
− | | 04 | + | | 04:06 |
|In this tutorial, we learnt | |In this tutorial, we learnt | ||
|- | |- | ||
− | | 04 | + | | 04:08 |
|About the pointer. | |About the pointer. | ||
|- | |- | ||
− | | 04 | + | | 04:10 |
|To create a pointer. | |To create a pointer. | ||
|- | |- | ||
− | | 04 | + | | 04:12 |
|And operation on pointer. | |And operation on pointer. | ||
|- | |- | ||
− | | 04 | + | | 04:14 |
|As an assignment, write a C and C++ program, | |As an assignment, write a C and C++ program, | ||
|- | |- | ||
− | | 04 | + | | 04:18 |
|To declare a variable and pointer. | |To declare a variable and pointer. | ||
|- | |- | ||
− | | 04 | + | | 04:21 |
| Store the address of variable in the pointer. | | Store the address of variable in the pointer. | ||
|- | |- | ||
− | | 04 | + | | 04:24 |
|And print the value of the pointer. | |And print the value of the pointer. | ||
|- | |- | ||
− | | 04 | + | | 04:27 |
|Watch the video available at the link shown below | |Watch the video available at the link shown below | ||
|- | |- | ||
− | | 04 | + | | 04:30 |
|It summarizes the Spoken Tutorial project | |It summarizes the Spoken Tutorial project | ||
|- | |- | ||
− | | 04 | + | | 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 | + | | 04:37 |
|The Spoken Tutorial Project Team | |The Spoken Tutorial Project Team | ||
|- | |- | ||
− | | 04 | + | | 04:39 |
|Conducts workshops using spoken tutorials | |Conducts workshops using spoken tutorials | ||
|- | |- | ||
− | |04 | + | |04:43 |
|Gives certificates to those who pass an online test | |Gives certificates to those who pass an online test | ||
|- | |- | ||
− | | 04 | + | | 04:47 |
|For more details, please write to, contact@spoken-tutorial.org | |For more details, please write to, contact@spoken-tutorial.org | ||
|- | |- | ||
− | | 04 | + | | 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 | + | | 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 | + | | 05:06 |
|More information on this Mission is available at the link shown below | |More information on this Mission is available at the link shown below | ||
|- | |- | ||
− | | 05 | + | | 05:10 |
| This is Ashwini Patil from IIT Bombay signing off | | This is Ashwini Patil from IIT Bombay signing off | ||
|- | |- | ||
− | | 05 | + | | 05:14 |
|Thank You for joining. | |Thank You for joining. |
Revision as of 15:42, 23 June 2014
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 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 few changes like the header file as iostream |
03:19 | Then we are using the std namespace |
03:23 | And 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 |
04:06 | 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