s WHEN TO THROW AN EXCEPTION in Software

Print Data Matrix 2d barcode in Software s WHEN TO THROW AN EXCEPTION
s WHEN TO THROW AN EXCEPTION
ECC200 Encoder In C#
Using Barcode encoder for VS .NET Control to generate, create Data Matrix 2d barcode image in Visual Studio .NET applications.
We have given some very simple code to illustrate the basic concepts of exception handling However, our examples were unrealistically simple A more complicated but better guideline is to separate throwing an exception and catching the exception into separate functions In most cases, you should include any throw statement within a function de nition, list the exception in an exception speci cation for that function, and place the catch clause in a different function Thus, the preferred use of the trythrow-catch triad is as illustrated here:
Data Matrix 2d Barcode Drawer In .NET Framework
Using Barcode creator for ASP.NET Control to generate, create Data Matrix image in ASP.NET applications.
void functionA( ) throw (MyException) { throw MyException(<Maybe an argument>); }
Generating Data Matrix In .NET Framework
Using Barcode creator for .NET Control to generate, create Data Matrix 2d barcode image in Visual Studio .NET applications.
Then, in some other function (perhaps even some other function in some other le), you have the following:
ECC200 Drawer In Visual Basic .NET
Using Barcode encoder for .NET framework Control to generate, create ECC200 image in .NET framework applications.
void functionB( ) {
Create Bar Code In .NET Framework
Using Barcode generator for ASP.NET Control to generate, create bar code image in ASP.NET applications.
Exception Handling
Barcode Generator In Java
Using Barcode printer for Java Control to generate, create barcode image in Java applications.
try { functionA( ); } catch(MyException e) {
Painting EAN13 In .NET Framework
Using Barcode maker for ASP.NET Control to generate, create GTIN - 13 image in ASP.NET applications.
<Handle exception>
Create GTIN - 13 In Java
Using Barcode creator for Java Control to generate, create GS1 - 13 image in Java applications.
} }
Barcode Maker In VB.NET
Using Barcode creation for Visual Studio .NET Control to generate, create barcode image in Visual Studio .NET applications.
Even this kind of use of a throw statement should be reserved for cases where it is unavoidable If you can easily handle a problem in some other way, do not throw an exception Reserve throw statements for situations in which the way the exceptional condition is handled depends on how and where the function is used If the way that the exceptional condition is handled depends on how and where the function is invoked, then the best thing to do is let the programmer who invokes the function handle the exception In all other situations, it is preferable to avoid throwing exceptions Let s outline a sample scenario of this kind of situation Suppose you are writing a library of functions to deal with patient monitoring systems for hospitals One function might compute the patient s average daily temperature by accessing the patients record in some le and dividing the sum of the temperatures by the number of times the temperature was taken Now suppose these functions are used for creating different systems to be used in different situations What should happen if the patient s temperature was never taken and so the averaging would involve a divides by zero In an intensive care unit, this would indicate something is very wrong, such as the patient is lost (It has been known to happen) So for that system, when this potential division by zero would occur, an emergency message should be sent out However, for a system to be used in a less urgent setting, such as outpatient care or even in some noncritical wards, it might have no signi cance and so a simple note in the patient s records would suf ce In this scenario the function for doing the averaging of the temperatures should throw an exception when this division by zero occurs, list the exception in the exception speci cations, and let each system handle the exception case in the way that is appropriate to that system
ANSI/AIM Code 128 Printer In Java
Using Barcode drawer for Java Control to generate, create Code128 image in Java applications.
Programming Techniques for Exception Handling
Barcode Generator In Java
Using Barcode generation for Java Control to generate, create barcode image in Java applications.
WHEN
Generate ANSI/AIM Code 128 In VS .NET
Using Barcode maker for ASP.NET Control to generate, create Code 128 Code Set B image in ASP.NET applications.
THROW
Data Matrix ECC200 Drawer In Java
Using Barcode creation for Java Control to generate, create ECC200 image in Java applications.
EXCEPTION
Printing Bar Code In C#
Using Barcode creation for Visual Studio .NET Control to generate, create barcode image in VS .NET applications.
For the most part, throw statements should be used within functions and listed in an exception specification for the function Moreover, they should be reserved for situations in which the way the exceptional condition is handled depends on how and where the function is used If the way that the exceptional condition is handled depends on how and where the function is invoked, then the best thing to do is let the programmer who invokes the function handle the exception In other situations, it is almost always preferable to avoid throwing an exception
EAN128 Drawer In Visual Studio .NET
Using Barcode creator for .NET framework Control to generate, create GS1 128 image in VS .NET applications.
Pitfall
Print Barcode In Visual Studio .NET
Using Barcode maker for .NET Control to generate, create barcode image in .NET applications.
UNCAUGHT EXCEPTIONS
Reading Code-39 In .NET Framework
Using Barcode scanner for .NET Control to read, scan read, scan image in .NET framework applications.
Every exception that is thrown by your code should be caught someplace in your code If an exception is thrown but not caught anywhere, the program will end Technically speaking, if an exception is thrown but not caught, then the function terminate( ) is called The default meaning for terminate( ) is to end your program You can change the meaning from the default, but that is seldom needed and we will not go into the details here An exception that is thrown in a function but is not caught either inside or outside the function has two possible cases If the exception is not listed in the exception specification, then the function unexpected( ) is called If the exception is not listed in the exception specification, the function terminate( ) is called But unless you change the default behavior of unexpected( ), unexpected( ) calls terminate( ) So, the result is the same in both cases If an exception is thrown in a function but not caught either inside or outside the function, then your program ends
Data Matrix Generator In Visual Studio .NET
Using Barcode maker for ASP.NET Control to generate, create Data Matrix ECC200 image in ASP.NET applications.
terminate()
UPCA Drawer In Visual Studio .NET
Using Barcode printer for Visual Studio .NET Control to generate, create UPC Symbol image in .NET framework applications.
unexpected()
Barcode Encoder In .NET
Using Barcode generator for Visual Studio .NET Control to generate, create barcode image in Visual Studio .NET applications.