View source for Advanced-C++/C2/Exception-Handling/English

'''Title of script''': Exception Handling in C++

'''Author: '''Ashwini Patil

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



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| style="background-color:#ffffff;border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.018cm;padding-right:0.018cm;"| <center>'''Narration'''</center>

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Learning Objectives



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Exception Handling.

We will do this with the help of an example.

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System requirements



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'''Ubuntu OS '''version 11.10

'''g++ compiler '''v. 4.6.1

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Introduction to Exception
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An exception is a problem that arises during the execution of a program

It is a run-time error that a program may detect

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Introduction to Exception Handling
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The response given to the problems occured during the execution of the program is known as exception handling.

Exception handling allows a program to continue execution.

Helps Identifying the problem.

Terminates the program in a controlled manner.

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Types of Exceptions
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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 statement

And then it is processed. 

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Syntax
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Throw:

try { 

// try block 

} 

catch (type1 arg) { 

// catch block 

} 

catch (type2 arg) { 

// catch block 

} 

The try block and the catch block, here we pass argument

The throw statement can be written inside the try block as well

We can have more than try, catch blocks.

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I have the code, i will explain it to you.

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In this program we will solve the divide by zero error using exception handling.

Let us go through the code

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'''<nowiki>#include <iostream> </nowiki>'''

'''using namespace std;'''
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Here we are using the '''std namespace.'''

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'''double division(int a, int b) '''

'''{ '''

'''if( b == 0 ) '''

'''{ '''

'''throw "Division by zero condition!"; '''

'''} '''

'''return (a/b); '''

'''}'''
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We check whether''' b ==0.'''

If true, we throw an exception division by zero condition

The function returns division of''' a '''and''' b'''




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'''int main()'''
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'''int x,y; '''

'''double z; '''

'''<nowiki>cout<<"Enter value of x and y\n"; </nowiki>'''

'''cin>>x>>y;'''
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Here we accept the values of''' x '''and''' y.'''




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'''try '''

'''{ '''

'''z = division(x, y); '''

'''<nowiki>cout << z<<"\n"; </nowiki>'''

'''}'''
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Here we have called the function''' division.'''

And stored the result in '''z.'''

Then we print the value of''' z.'''

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'''catch (const char* msg) '''

'''{ '''



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In this we pass an''' argument msg '''as a''' character constant.'''

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'''<nowiki>cout << msg << endl; </nowiki>'''

'''} '''
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'''return 0;'''
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'''Ctrl, Alt and T '''keys simultaneously
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'''g++ exception.cpp -o exp'''

To execute

Type

'''./exp'''
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'''g++ exception.cpp -o ex'''

To execute

Type

'''./ex'''

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'''Output'''
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'''Enter the value of x and y:'''

'''I will first enter as 3 and 0'''

'''The output is displayed as:'''

'''Division by zero condition'''

'''Let us compile again'''

'''Press the up arrow key twice '''

'''Press enter, again press the up arrow key twice'''

'''Enter value of x and y'''

'''i will give as 8 and 2'''

'''The output is 4'''




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Let us come back to our slides

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Summary
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Exception Handling

Try

Catch

Throw blocks

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Assignment
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Display the age of employess.

Throw an exception to check that the age is not less than 15.

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About the Spoken Tutorial Project
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It summarizes the Spoken Tutorial project 

If you do not have good bandwidth, you can download and watch it

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Spoken Tutorial Workshops
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Conducts workshops using spoken tutorials 

Gives certificates to those who pass an online test 

For more details, please write to,

contact@spoken-tutorial.org

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Acknowledgement
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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 http://spoken-tutorial.org\NMEICT-Intro]

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Thank You for joining. 

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