C-and-C++/C4/Understanding-Pointers/English-timed

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.
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