PPL: Exception Handling

C++ Exception Handling

#include < iostream.h>

using namespace std;

void main()

{

int x,y;

cout<<"Enter the value of x:";

cin>>a>>b;

cout<<"Enter the value of y:";

cin>>b;

try

{

if(y!=0)

{

cout<<"Result=" << x/y;

}

else

{

throw(y);

}

catch(int ex)

{

cout<<"Caught an exception which is:" << y ;

           }

}

}

OUTPUT:

Enter the value of a:

4

Enter the value of b;

0

Caught an exception which is:0

First we should know what is exception handling?

Ans. When in a program a situation occurred when program is not able to take decision or result is out of control. Than such conditions are needed to be handled to prevent our program. The reason behind such conditions is known as exceptions.

Some of the examples of exceptions are:

• When divided by zero(o), which is an exception.
• When doing operation of a number with a character, is also an exception.
• Pressing a login button may time after entering credentials, could also be an exception.

So, for handling exceptions in a program which may be in C++, JAVA etc. Concept of exception handling is used.

In exception handling, try and catch blocks are used. In try, throw is also used.

The try block will execute the program, and if any exception occurs it will throw the exception and program control will entered into catch block.

The try block is always used to execute the program and catch block will always handled the exceptions thrown by try block.

MCQs on Exception Handling

Q1. The class at the top of exception class hierarchy is __________.

A. Arithmetic exception  

B. Throwable   

C. Object    

D. Exception

MCQs Answers

Q1. (B)

Principles of Programming Languages:

EasyExamNotes.com covered following topics in PPL.

• Language Evaluation Criteria
• Influences on Language Design 
• Language Categories
• Programming Paradigms
• Compilation
• Virtual Machines 
• Programming Environments
• Issues in Language Translation
• Parse Tree 
• Pointer and Reference type
• Concept of Binding
• Type Checking
• Strong typing 
• Sequence control with Expression
• Exception Handling 
• Subprograms
• Fundamentals of sub-programs
• Scope and lifetime of variable
• Static and dynamic scope
• Design issues of subprogram and operations
• Local referencing environments
• Parameter passing methods
• Overloaded sub-programs
• Generic sub-programs 
• Design issues for functions 
• Co routines 
• Abstract Data types
• Abstraction and encapsulation
• Static and Stack-Based Storage management
• Garbage Collection
• OOP in C++
• OOP in Java 
• OOP in C# 
• OOP in PHP
• Concurrency
• Semaphores 
• Monitors
• Message passing
• Java threads 
• C# threads 
• Exception handling 
• Exceptions
• Exception Propagation 
• Exception handler in C++ 
• Exception handler in Java
• Introduction and overview of Logic programming
• Basic elements of Prolog
• Application of Logic programming
• Functional programming languages
• Introduction to 4GL 

Practicals:

• Memory Implementation of 2D Array. 
• Memory Implementation of 3D Array. 
• Implementation of pointers in C++. 
• Write a program in Java to implement exception handling.
• Write a program in C++ to implement call by value parameter passing Method.
• Write a program in C++ to implement call by reference parameter passing Method. 
• Write a program in Java to implement concurrent execution of a job using threads.
• Implement Inheritance in C#.
• Implement Encapsulation in C#.
• Implement static/compiletime Polymorphism in C#.
• Implement dynamic/runtime Polymorphism in C#.

Previous years solved papers:

• PPL|RGPV|May 2018 
• PPL|RGPV|June 2017 

A list of Video lectures

• Click here

References:

1. Sebesta,”Concept of programming Language”, Pearson Edu 
2. Louden, “Programming Languages: Principles & Practices” , Cengage Learning 
3. Tucker, “Programming Languages: Principles and paradigms “, Tata McGraw –Hill. 
4. E Horowitz, "Programming Languages", 2nd Edition, Addison Wesley