Question

12.5 Program: Divide by Zero (C++)

This program will test exception handling during division.

The user will enter 2 numbers and attempt to divide (in a try block) the 1st number by the 2nd number.

The program will provide for 2 different catch statements:

Division by zero - denominator is zero

Division results in a negative number

The user should be prompted with Enter 2 numbers:

For input of 7 and 0 the output should be Exception: Division by zero

For input of 7 and 2 the output should be a/b = 3.5

For input of 7 and -2 the output should be Exception: Division is negative

L

Lab Submission

12.5.1: Program: Divide by Zero

Instructions Deliverables DivideByZero.cpp We will expect the above file(s) to be submitted Compile command g++ DivideByZero.cpp -Wall -o a.out We will use this command to compile your code

Answer 1

Exceptions are runtime errors that a program encounters during execution.

Exception handling mechanism is used which identifies and deal with such condition. Exception handling mechanism consists of following parts:

Find the problem (Hit the exception)
Inform about its occurrence (Throw the exception)
Receive error information (Catch the exception)
Take proper action (Handle the exception)

3 keywords for handling the exception in c++ language. They are

1. try: Try block consists of the code that may generate exception. Exception are thrown from inside the try block.
2. throw: Throw keyword is used to throw an exception encountered inside try block. After the exception is thrown, the control is transferred to catch block.
3. catch: Catch block catches the exception thrown by throw statement from try block. Then, exception are handled inside catch block.

Syntax

try

{

    statements;

    ... ... ...

    throw exception;

}

catch (type argument)

{

    statements;

    ... ... ...

}

Multiple catch exception

Multiple catch exception statements are used when a user wants to handle different exceptions differently. For this, a user must include catch statements with different declaration.

Syntax

try
{
    body of try block
}

catch (type1 argument1)
{
    statements;
    ... ... ...
}

catch (type2 argument2)
{
    statements;
    ... ... ...
}
... ... ...
... ... ...
catch (typeN argumentN)
{
    statements;
    ... ... ...
}

Program code:

#include <iostream>

using namespace std;

int main() //tesitng for program

{

    int a,b; //Declare the variables

    cout << "Enter 2 numbers: ";

    cin >> a >> b;

    try

    {

        if (b != 0)

        {

            float div = (float)a/b;

            if (div < 0)

                throw 'e';

            cout << "a/b = " << div;

        }

        else

            throw b;

           

    }

    catch (int e)

    { //exception1

        cout << "Exception: Division by zero"<<endl;

    }

  

    catch(...) //exception2

    { // it can catch all those exception which are not handled by other catch statements.

        cout << "Exception: Division is negative"<<endl;

    }

    return 0;

}

output is:

Example1:

sh-4.2$ g+ -o main *.cpp sh-4.2$ main Enter 2 numbers: 7 0 Exception: Division by zero

Example2:

Default Term Browser sh-4.2$ g++ -o main *.cpp sh-4.2$ main Enter 2 numbers 7 2 a/b 3.5

Example3:

sh-4.2$ g++ -o main .cpp sh-4.2$ main Enter 2 numbers: 7 2 Exception: Division is negative sh-4.2$