c# ean 13 check digit CODING HORROR in Visual C#.NET

Generating EAN-13 Supplement 5 in Visual C#.NET CODING HORROR

CODING HORROR
GTIN - 13 Generation In C#.NET
Using Barcode generation for .NET framework Control to generate, create EAN-13 Supplement 5 image in .NET framework applications.
www.OnBarcode.com
Recognizing EAN13 In C#.NET
Using Barcode recognizer for VS .NET Control to read, scan read, scan image in VS .NET applications.
www.OnBarcode.com
Java Example of a Comment That Focuses on How
Barcode Drawer In Visual C#
Using Barcode printer for VS .NET Control to generate, create bar code image in Visual Studio .NET applications.
www.OnBarcode.com
Recognize Bar Code In Visual C#.NET
Using Barcode decoder for .NET framework Control to read, scan read, scan image in Visual Studio .NET applications.
www.OnBarcode.com
// if account flag is zero if ( accountFlag == 0 ) ...
EAN / UCC - 13 Generation In .NET Framework
Using Barcode creator for ASP.NET Control to generate, create EAN 13 image in ASP.NET applications.
www.OnBarcode.com
Draw GTIN - 13 In VS .NET
Using Barcode printer for Visual Studio .NET Control to generate, create EAN13 image in VS .NET applications.
www.OnBarcode.com
The comment tells you nothing more than the code itself does. What about this comment
EAN13 Creation In Visual Basic .NET
Using Barcode printer for .NET framework Control to generate, create EAN / UCC - 13 image in .NET applications.
www.OnBarcode.com
Print ECC200 In Visual C#
Using Barcode maker for .NET framework Control to generate, create DataMatrix image in Visual Studio .NET applications.
www.OnBarcode.com
Java Example of a Comment That Focuses on Why
Barcode Drawer In C#.NET
Using Barcode creation for Visual Studio .NET Control to generate, create bar code image in .NET framework applications.
www.OnBarcode.com
Matrix Barcode Drawer In C#.NET
Using Barcode generation for .NET Control to generate, create 2D Barcode image in .NET framework applications.
www.OnBarcode.com
// if establishing a new account if ( accountFlag == 0 ) ...
EAN / UCC - 13 Maker In Visual C#
Using Barcode encoder for VS .NET Control to generate, create EAN 128 image in .NET framework applications.
www.OnBarcode.com
Identcode Printer In Visual C#
Using Barcode creator for Visual Studio .NET Control to generate, create Identcode image in Visual Studio .NET applications.
www.OnBarcode.com
This comment is a lot better because it tells you something you couldn t infer from the code itself. The code itself could still be improved by use of a meaningful enumerated type name instead of O and a better variable name. Here s the best version of this comment and code:
UPC-A Maker In None
Using Barcode encoder for Font Control to generate, create UPC-A Supplement 2 image in Font applications.
www.OnBarcode.com
Scan GS1-128 In Visual C#
Using Barcode decoder for .NET framework Control to read, scan read, scan image in .NET framework applications.
www.OnBarcode.com
Java Example of Using Good Style In Addition to a Why Comment
Paint Universal Product Code Version A In Java
Using Barcode creation for Android Control to generate, create UPC-A Supplement 2 image in Android applications.
www.OnBarcode.com
Matrix Barcode Creator In Java
Using Barcode maker for Java Control to generate, create Matrix Barcode image in Java applications.
www.OnBarcode.com
// if establishing a new account
Making QR Code In .NET Framework
Using Barcode drawer for ASP.NET Control to generate, create QR Code ISO/IEC18004 image in ASP.NET applications.
www.OnBarcode.com
Encode EAN13 In None
Using Barcode maker for Software Control to generate, create GTIN - 13 image in Software applications.
www.OnBarcode.com
de Complete
Encoding UPC Symbol In Objective-C
Using Barcode drawer for iPad Control to generate, create Universal Product Code version A image in iPad applications.
www.OnBarcode.com
EAN 13 Generation In .NET Framework
Using Barcode printer for ASP.NET Control to generate, create EAN / UCC - 13 image in ASP.NET applications.
www.OnBarcode.com
32. Self-Documenting Code
Page 23
if ( accountType == AccountType.NewAccount ) ...
When code attains this level of readability, it s appropriate to question the value of the comment. In this case, the comment has been made redundant by the improved code, and it should probably be removed. Alternatively, the purpose of the comment could be subtly shifted, like this:
Java Example of Using a Section Heading Comment
// establish a new account if ( accountType == AccountType.NewAccount ) { ... }
If this comment documents the whole block of code following the if test, then it serves as a summary-level comment, and it s appropriate to retain it as a section heading for the paragraph of code it references.
Use comments to prepare the reader for what is to follow Good comments tell the person reading the code what to expect. A reader should be able to scan only the comments and get a good idea of what the code does and where to look for a specific activity. A corollary to this rule is that a comment should always precede the code it describes. This idea isn t always taught in programming classes, but it s a well-established convention in commercial practice. Make every comment count There s no virtue in excessive commenting. Too many comments obscure the code they re meant to clarify. Rather than writing more comments, put the extra effort into making the code itself more readable. Document surprises If you find anything that isn t obvious from the code itself, put it into a comment. If you have used a tricky technique instead of a straightforward one to improve performance, use comments to point out what the straightforward technique would be and quantify the performance gain achieved by using the tricky technique. Here s an example:
C++ Example of Documenting a Surprise
for ( element = 0; element < elementCount; element++ ) { // Use right shift to divide by two. Substituting the // right-shift operation cuts the loop time by 75%. elementList[ element ] = elementList[ element ] >> 1; }
The selection of the right shift in this example is intentional. Among experienced programmers, it s common knowledge that for integers, right shift is functionally equivalent to divide-by-two.
de Complete
32. Self-Documenting Code
Page 24
If it s common knowledge, why document it Because the purpose of the operation is not to perform a right shift; it is to perform a divide-by-two. The fact that the code doesn t use the technique most suited to its purpose is significant. Moreover, most compilers optimize integer division-by-two to be a right shift anyway, meaning that the reduced clarity is usually unnecessary. In this particular case, the compiler evidently doesn t optimize the divide-by-two, and the time saved will be significant. With the documentation, a programmer reading the code would see the motivation for using the nonobvious technique. Without the comment, the same programmer would be inclined to grumble that the code is unnecessarily clever without any meaningful gain in performance. Usually such grumbling is justified, so it s important to document the exceptions.
Avoid abbreviations Comments should be unambiguous, readable without the work of figuring out abbreviations. Avoid all but the most common abbreviations in comments.
Unless you re using endline comments, using abbreviations isn t usually a temptation. If you are, and it is, realize that abbreviations are another strike against a technique that struck out several pitches ago.
Differentiate between major and minor comments In a few cases, you might want to differentiate between different levels of comments, indicating that a detailed comment is part of a previous, broader comment. You can handle this in a couple of ways.
You can try underlining the major comment and not underlining the minor comment, as in the following:
Copyright © OnBarcode.com . All rights reserved.