Difference between revisions of "C-and-C++/C4/Understanding-Pointers/English-timed"
From Script | Spoken-Tutorial
(Created page with '{| border=1 || ''Time''' || '''Narration''' |- | 00:02 |Welcome to the spoken tutorial on Pointers in C and C++ |- | 00:07 |In this tutorial we will learn |- | 00:09 | Pointer…') |
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Revision as of 12:13, 11 September 2013
| Time' | Narration |
| 00:02 | Welcome to the spoken tutorial on Pointers in C and C++ |
| 00:07 | In this tutorial we will learn |
| 00:09 | Pointers. |
| 00:10 | To create Pointers. |
| 00:12 | And operations on Pointer. |
| 00:15 | We will do this with the help of an example. |
| 00:18 | To record this tutorial I am using
Ubuntu OS v11.10 gcc and g++ compiler v4.6.1 on ubuntu.
|
| 00:32 | Let us start with an introduction to pointers. |
| 00:35 | Pointers point to the locations in memory.
|
| 00:39 | Pointers store a memory address.
|
| 00:42 | It also gives value stored at that address. |
| 00:45 | Now let us see an example on pointers. |
| 00:49 | Note that our file name is pointers_demo.c
|
| 00:54 | Let us go through the code now |
| 00:57 | This is our headerfile as stdio.h |
| 01:01 | 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. |
| 01:13 | 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. |
| 01:34 | This statement will print the address of the variable num. |
| 01:38 | Over here ptr stores the address of num. |
| 01:48 | This statement will print the address of ptr. |
| 01:46 | Size of function will give the size of ptr. |
| 01:49 | This is will give the value of ptr. |
| 01:52 | That is the memory address of num. |
| 01:55 | And here asterisk ptr will give the value at the address.
' |
| 02:00 | So using asterik will not give the memory address. |
| 02:03 | Instead it will give the value. %ld is the format specifier for long int. |
| 02:11 | Now let us execute the program. |
| 02:14 | Open the terminal window by pressing ctrl+alt+t keys simultaneously on your keyboard. |
| 02:22 | To compile type: |
| 02:23 | gcc pointers_demo.c -o point |
| 02:33 | Press Enter |
| 02:35 | type ./point.Press Enter |
| 02:39 | The output is displayed |
| 02:42 | We see that the num address and ptr value is same. |
| 02:48 | Whereas 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 |
| 03:04 | Now let us see the same program in C++. |
| 03:08 | Note that our filename is pointers_demo.cpp |
| 03:14 | Here we have a few changes like the header file as isotream
' |
| 03:20 | 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. |
| 03:31 | Let us execute the program |
| 03:33 | Come back to our terminal. |
| 03:35 | To compile type: |
| 03:36 | g++ pointers_demo.cpp -o point1 |
| 03:48 | Press Enter |
| 03:51 | Type:./point1. Press Enter |
| 03:56 | You 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 slides. |
| 04:06 | Let us summarize: |
| 04:07 | In this tutorial we learnt. |
| 04:09 | About the pointer. |
| 04:11 | To create a pointer. |
| 04:12 | And Operation on pointer. |
| 04:15 | As an assignment write a C and C++ program,
|
| 04:18 | To declare a variable and pointer. |
| 04:22 | Store the address of variable in the pointer. |
| 04:25 | And Print the value of the pointer.
|
| 04:28 | Watch the video available at http://spoken-tutorial.org/What_is_a_Spoken_Tutorial |
| 04:31 | It summarizes the Spoken Tutorial project |
| 04:33 | If you do not have good bandwidth, you can download and watch it
|
| 04:38 | The Spoken Tutorial Project Team |
| 04:40 | Conducts workshops using spoken tutorials |
| 04:43 | Gives certificates for those who pass an online test
|
| 04:47 | For more details, please write to contact@spoken-tutorial.org
|
| 04:54 | 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
|
| 05:11 | This is Ashwini Patil from IIT Bomabay. Siginning off. |
| 05:15 | Thanks for joining. |
Contributors and Content Editors
Kavita salve, Krupali, PoojaMoolya, Pratik kamble, Sandhya.np14, Sneha
