C-and-C++/C4/Function-Call/English-timed

Time'	Narration
00:02	Welcome to the spoken tutorial on Function call in C and C++
00:08	In this tutorial we will learn about type of function calls namely, call by value.
00:15	call by reference.
00:17	We will do this through an example.
00:20	To record this tutorial, I am usingUbuntu Operating system version 11.10gcc and g++ Compiler version 4.6.1
00:32	Let us start with the introduction to functions call by value
00:37	It is a method of passing arguments to the function.
00:40	When we pass a variable by value it makes a copy of the variable.
00:46	Before passing to the function.
00:49	Changes made to the arguments inside the function will remain in the function.
00:55	It will not be affected outside the function.
00:59	Let us see a program on function call by value.
01:02	I have already typed the program on the editor. i will just open it.
01:08	Please note our filename is callbyval.c.
01:13	In this program we will calculate the cube of a number. Let me explain the code now.
01:20	This is our header file
01:22	Here we have function cube having an argument as int x.
01:28	In this function we calculate the cube of x and return the value of x.
01:34	This is our main function.
01:37	Here we give the value of n as 8. n is an integer variable
01:44	Then we call the function cube.
01:46	And print the value of n and the cube of n.
01:50	And This is our return statement.
01:53	Now let us execute the program.
01:55	open the terminal window by pressing ' Ctrl, Alt and T keys simultaneously on your keyboard.
02:03	To compile , type
02:04	gcc callbyval.c -o val. Press Enter
02:13	Now type ./val.Press Enter
02:17	The output is displayed as Cube of 8 is 512.
02:23	Now we will see function call by reference.
02:27	Let us go back to our slides.
02:29	It is another method of passing arguments to the function.
02:34	This method copies the address of the argument instead of the value.
02:40	Changes made to the arguments inside a function can affect them outside.
02:46	In this we need to declare the arguments as pointer type.
02:51	Let us see an example on function call by reference.
02:55	Note that our filename is callbyref.c
02:59	This is our headerfile as stdio.h
03:03	Then we have function swap
03:06	This function will exchange the values of the variables.
03:11	Value of *a will be stored in value of *b and vice-versa.
03:16	You can see that the arguments passed in the function are pointer type.
03:22	Here we have declared an integer variable t.
03:25	First value of *a is stored in t.
03:29	Then value of *b is stored in *a.
03:33	And Then value of t is stored in *b .
03:37	Like this the values are exchanged.
03:40	This is our main function.
03:43	Here we have declared two integer variables as i and j .
03:49	Then we take the values of i and j as user inputs.
03:54	&i and &j will give the memory address of i and j.
04:00	First we print the values before swapping.
04:05	Then we call the function swap
04:07	And then we print the values after swapping.
04:11	And This is our return statement.
04:14	Now let us execute the program
04:17	Switch back to our terminal
04:19	To compile type
04:22	gcc callbyref.c -o ref. Press Enter
04:30	Now type ./ref. Press Enter
04:34	We see, enter the values I will enter as 6 and 4
04:40	The output is displayed as,before swapping 6 and 4
04:45	After swapping 4 and 6
04:48	NOW LET US SEE HOW TO EXECUTE THE SAME PROGRAM IN C++
04:53	I have the code, lets go through it.
04:58	This is the second program function callbyreference .
05:02	Note that our filename is callbyref.cpp
05:07	Let us go through the code now
05:09	This is ou header file as iostream
05:13	Here we are using the std namespace
05:16	The function declaration is same in C++.
05:20	In this we pass the arguments as &x and &y.
05:25	This will give the memory address of x and y.
05:30	Then we swap the values.
05:33	Rest of the code is similar to our C code.
05:37	The printf' statement is replaced by cout and the scanf statement is replaced by cin
05:44	Now let us execute the program. Come back to our terminal
05:49	To compile type; g++callbyref.cpp -o ref1 press Enter
06:01	Now Type ./ref1, Press Enter
06:06	Here it is displayed as:
06:07	Enter values of a and b
06:10	I will enter as 4 and 3
06:14	The output is displayed
06:16	Before swapping a and b: 4 and 3
06:20	After swapping a and b: 3 and 4
06:24	This brings us to the end of this tutorial.
06:27	Let us go back to our slides.
06:30	Let us summarize, In this tutorial we learn't:
06:33	Function call by value.
06:35	And Function call by reference.
06:38	As an assignment
06:39	Write a similar program to calculate the cube of a number.
06:43	Using call by value in C++.
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07:27	This is Ashwini Patil from IIT Bombay. Signing off. Thank You for joining

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Kavita salve, Krupali, PoojaMoolya, Pratik kamble, Sandhya.np14, Sneha