Advanced-C++/C2/Exception-Handling/English

Title of script: Objects and Classes in C++

Author: Ashwini Patil

Keywords: Exception handling, try, catch, throw Video tutorial.

Visual Cue	Narration
Slide 1	Welcome to the spoken tutorial on Exception Handling in C++.
Slide 2	In this tutorial we will learn, Exception Handling. We will do this with the help of an example.
Slide 3	To record this tutorial, I am using Ubuntu OS version 11.04 gcc and g++ compiler v. 4.6.1
Slide 4	Let us start with the introduction to exception handling. The response given to the problems occured during the execution of the program. Exception handling allows a program to continue execution. Helps Identifying the problem. Terminates the program in a controlled manner.
Slide 5	Types of Exception handling Try Catch Throw We place the error prone code inside a try block Then it is Handled using throw. after this the exception is caught, using catch And it is processed.
Slide 5	The syntax for try catch is: try { // try block } catch (type1 arg) { // catch block } catch (type2 arg) { // catch block } As we discussed earlier, When an exception is thrown it is cought by the catch statement. We can have more than one try-catch blocks.
	Now let us see an example on exception handling. I have the code, i will explain it to you.
	our filename is exception.cpp In this program we will solve the divide by zero error using exception handling. Let me explain the code now.
Highlight #include <iostream> using namespace std;	This is our header file as iostream. We have used std namespace.
Highlight double division(int a, int b) { if( b == 0 ) { throw "Division by zero condition!"; } return (a/b); }	Here we have function division with argument as int a and int b. We check whether b ==0. If true, we throw an exception. The function returns division of a and b
Highlight int main()	This is our main function.
Highlight int x,y; double z; cout<<"Enter value of x and y\n"; cin>>x>>y;	Here we have declared three variables as x, y and z. Then we accept the values of x and y from user.
Highlight try { z = division(x, y); cout << z<<"\n"; }	This is our try block Inside it we use call the function division. It is stored in z. Then we print the value of z.
Highlight catch (const char* msg) {	Here is our catch block. We pass an argument msg as a character constant.
Highlight cout << msg << endl; }	Then we print the msg.
Highlight return 0;	This is our return statement.
Click on save	Now Click on Save
	Let us execute
Open the terminal Ctrl, Alt and T keys simultaneously	open the terminal by pressing Ctrl, Alt and T keys simultaneously
Type g++ exception.cpp -o exp To execute Type ./exp	To compile the program type g++ exception.cpp -o exp To execute Type ./exp
Highlight Output	Here we see, Enter the value of x and y: I will first enter as 20 and 2 The output is displayed as: 10. Now let us execute again This time i will enter the values as 30 and 0 The output is displayed as: Divide by zero condition.
	This is how the try catch block works.
Switch back to the slides	This brings us to the end of this tutorial. Let us come back to the slides
Slide 7 Summary	In this tutorial, we have seen, Exception Handling Try Catch Throw
Slide 6 Assignment	As an assignment Display the age of employess. Throw an exception to check that the age is not less than 15.
Slide 8 About the Spoken Tutorial Project	Watch the video available at the link shown It summarizes the Spoken Tutorial project If you do not have good bandwidth, you can download and watch it
Slide 9 Spoken Tutorial Workshops	The Spoken Tutorial Project Team Conducts workshops using spoken tutorials Gives certificates to those who pass an online test For more details, please write to, contact@spoken-tutorial.org
Slide Number 10 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 Indiaabout:startpage More information on this Mission is available at: http://spoken-tutorial.org\NMEICT-Intro
	This is Ashwini Patil from IIT Bombay signing off Thank You for joining.

Contributors and Content Editors

Ashwini