C-and-C-Plus-Plus/C2/Arithmetic-Operators-in-C-and-C-Plus-Plus/English

Title of script: Arithmetic Operators in C and C++

Author: Ritwik Joshi

Keywords: Arithmetic Operators, Video Tutorial

Visual Cue	Narration
Slide 1	Welcome to the spoken tutorial on Arithmetic Operators in C C++.
Slide 2	In this tutorial, we will learn: Arithmetic operators + Addition: eg. a+b. - Subtraction: eg. a-b. / Division: eg. a/b. * Multiplication: eg. a*b. % Modulus: eg. a%b.
Slide 3	To record this tutorial, I am using: Ubuntu 11.10 as the operating system and gcc and g++ Compiler version 4.6.1 in Ubuntu.
	I will now demonstrate the use of these arithmetic operations with the help of a C program.
Switch to the file arithmetic.c in gedit	I have already written the program. So I will open the editor and explain the code.
Highlight int a,b; float c; a=5; b=2;	Here is the C program for arithmetic operators. In the first four statements the variables are declared and defined. In the next two statements, a is assigned the value of 5. b is assigned the value of 2.
Highlight c=a+b;	Now let's see how the addition operator works. c holds the sum of a and b.
Highlight printf("Addition of a and b is %.2f\n",c);	This printf statement displays the sum of a and b on the screen. Here %.2f provides the precision of two digits after the decimal point.
Highlight c=a*b;	In the next statement, c holds the product of a and b.
Highlight printf("Multiplication of a and b is %.2f\n",c);	This printf statement displays the product of a and b on the screen. Let's see how these two operators work.
Type /* */	Now let us comment these lines Type /* */
Click on Save	Click on Save to save the program. Save the file with extension .c I have saved the file as arithmetic.c
press Ctrl, Alt and T keys simultaneously.	Open the terminal window by pressing Ctrl, Alt and T keys simultaneously.
Type gcc incr.c -o incr Type ./incr	To compile, type the following on the terminal gcc arithmetic.c -o arith Press Enter To execute the code, type ./arith
	press Enter
Output	The output is displayed on the screen. It shows, Sum of a and b is 7.00 and Product of a and b is 10.00
Assignment	Now you should try the subtraction operator on your own Try replacing the addition operator with subtraction operator. You should get the result as 3.
Switch back to the editor Delete /* and */	Coming back to the program and the last set of statements. Now, I will explain the code for division. Remove the multi line comments from here and here.
Highlight c=a/b;	In these statements, c holds the value of integer division of a and b. Please note that in integer division the fractional part is truncated.
Highlight printf("Integer Division of a and b is %.2f\n", c);	The printf statement displays the division output on the screen.
Highlight c=(float)a/b;	In this statement we are performing real division. Here one of the operands has to be cast as float The printf statement displays the output of real division on the screen. For real division, one of the operands has to be cast as float.
Highlight printf("Real Division of a and b is %.2f\n",c);	We have type-cast variable a. Now a will behave as a float varibale for a single operation.
return 0; }	Type return 0 and close the ending curly bracket.
Click on Save	Click on Save.
Switch back to the terminal.	Coming back to the terminal to compile and execute the code.
Type gcc incr.c -o incr Type ./incr	To compile, type the following on the terminal gcc arithmetic.c -o arith To execute the code, type ./arith
Output	The output is displayed on the screen: We have the previous outputs of addition and multiplication operators. Addition of a and b is 7.00 Multiplication of a and b is 10.00 We have the Integer Division of 5 and 2 is 2.00 We can see that in integer division the fractional part is truncated. Then we have the Real Division of 5 and 2 is 2.50 In real division the result is as expected. We used type-casting to obtain these result.
	Now suppose, I want to write the same program in C++. Let see can we use the same code in C++, too?
Switch back to the editor	Let's find out. Let me go back to the editor.
Click on the C++ file in the editor	Here is a C++ file with the necessary code.
// Arithmetic Operators in C++ #include <iostream> using namespace std;	Notice that the header is different from the C file header. namespace is also used here.
int main() { int a,b; float c; a=5; b=2; c=a+b; cout <<"Addition of a and b is " <<c <<"\n"; c=a*b; cout <<"Multiplication of a and b is " <<c <<"\n"; c=a/b; cout <<"Integer Division of a and b is " <<c <<"\n"; c=(float)a/b; cout <<"Real Division of a and b is " <<c <<"\n"; return 0; }	Also, notice that the output statement in C++ is cout.
	So, apart from these differences, the two codes are very similar.
Click on Save. point to .cpp	Click on Save. Make sure the file is saved with the extension .cpp I have saved my file as arithmetic.cpp
On the terminal type g++ arithmetic.cpp -o arithmetic	Let's execute the code and seewhat results we get. Open the terminal and type g++ arithmetic.cpp -o arith Press Enter
On the terminal type ./ arithmetic	Let's execute this code and see what results we get. Type ./ arith
	Here the output is displayed: Addition of a and b is 7.00 Multiplication of a and b is 10.00 Integer Division of a and b is 2.00 Real Division of a and b is 2.50 So, we see that the results are identical. The only difference is in the precisions of outputs.
Summary:	Let us now summarize the tutorial. In this tutorial we learnt how to use the arithmetic operators.
Assignment:	As an assignment: Write a program to demonstrate the use of modulus operator. Please note that Modulus operator finds the remainder of division. eg. c = a % b; You should obtain the result as 1.
Slide 4 About the Spoken Tutorial Project Watch the video available at http://spoken-tutorial.org/What_is_a_Spoken_Tutorial It summarises the Spoken Tutorial project If you do not have good bandwidth, you can download and watch it	* Watch the video available at the following link It summarises the Spoken Tutorial project If you do not have good bandwidth, you can download and watch it
Slide 5 Spoken Tutorial Workshops The Spoken Tutorial Project Team Conducts workshops using spoken tutorials Gives certificates for those who pass an online test For more details, please write to contact@spoken-tutorial.org	The Spoken Tutorial Project Team * Conducts workshops using spoken tutorials Gives certificates for those who pass an online test For more details, please write to contact at spoken hyphen tutorial dot org
Slide 6 Acknowledgement Spoken Tutorial Project is a part of the Talk to a Teacher project It is supported by the National Mission on Education through ICT, MHRD, Government of India More information on this Mission is available at http://spoken-tutorial.org/NMEICT-Intro	Spoken Tutorial Project is a part of the Talk to a Teacher project It is supported by the National Mission on Education through ICT, MHRD, Government of India More information on this Mission is available at spoken hyphen tutorial dot org slash NMEICT hyphen Intro
Remain on previous slide No slide for this part	This is Ritwik Joshi from IIT Bombay. Thank you for joining.

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