An exception is literally that: an exception. Exceptions are thrown when something that shouldn't happen does. For example, if you're trying to turn "Hi" into an Integer, you'll get a NumberFormatException (in Java.) If there is nothing in place to handle an exception, the program will crash. Try-catch blocks are used for exception handling within methods, and exception throwing is used to give out exceptions, or let a different method handle it.
Example program (Java):
class ex{
public static void main(String[] args){
String Strx = "5a";
int x = 0;
try{
x += Integer.parseInt(Strx);
}catch(NumberFormatException e){ // If Strx is not an Integer
x += Integer.parseInt("5");
}
System.out.println("The value of x is " + x); // The value of x is 5
}
}
Alternatively, you could remove the try-catch blocks, and simply write "public static void main(String[] args) throws NumberFormatException" in the 2nd line of the program.
Here is a code snippet illustrating exception handling: try { int a= 3 / 0 ; } catch ( ArithmeticException e ) { System.out.println ("An ArithmeticException has occured"); } finally { // some code }
Error occurs at runtime and cannot be recovered, Outofmemory is one such example. Exceptions on the other hand are due conditions which the application encounters, that can be recovered such as FileNotFound exception or IO exceptions
A non-caught exception is propagated out of the local catch block into the next catch block, daisy chaining to the outermost catch block in the run-time library, where it will be handled by abending the program.
Explain the following terms in the context of object oriented programming. Also explain how these concepts are implemented in C++ by giving an example program for each.
The phenomenon where the object outlives the program execution time & exists between execution of a program is known as persistance
Here is a code snippet illustrating exception handling: try { int a= 3 / 0 ; } catch ( ArithmeticException e ) { System.out.println ("An ArithmeticException has occured"); } finally { // some code }
Error occurs at runtime and cannot be recovered, Outofmemory is one such example. Exceptions on the other hand are due conditions which the application encounters, that can be recovered such as FileNotFound exception or IO exceptions
A non-caught exception is propagated out of the local catch block into the next catch block, daisy chaining to the outermost catch block in the run-time library, where it will be handled by abending the program.
Explain the following terms in the context of object oriented programming. Also explain how these concepts are implemented in C++ by giving an example program for each.
When an exception occurs in program execution. Such as 1/0 or divide by zero exception. The program must catch the exception or the program will crash. Although handling of the exception or solution is not necessary.
An exception is abnormal program flow, so handling the exception is the very definition of resolving the abnormality.
The phenomenon where the object outlives the program execution time & exists between execution of a program is known as persistance
A compiler for the Java programming language checks, at compile time, that a program contains handlers for checked exceptions, by analyzing which checked exceptions can result from execution of a method or constructor. For each checked exception which is a possible result, the throws clause for the method or constructor must mention the class of that exception or one of the superclasses of the class of that exception. This compile-time checking for the presence of exception handlers is designed to reduce the number of exceptions which are not properly handled.
Trapping and handling of runtime errors is one of the most crucial taska ahead of any programmer. AS A DEVELOPER, YOU SOMETIMES SEEM TO SPEND MORE TIME CHECKING FOR ERRORS AND HANDLING THEM THEN YOU DO ON THE CORE LOGIC OF THE ACTUAL PROGRAM.
Because you can and you should, unless you want your program to crash if an exception occurs.
I need an example of a real-world array
No Not necessarily.. You can catch an exception and then continue to execute your program as if nothing happened. If in your catch block you have code like System.exit then your program would terminate.