de Complete in C#.NET

Drawer UPC - 13 in C#.NET de Complete

In languages that don t support namespaces or packages, you can still use naming conventions to partition the global name space. One convention is to require that globally-visible classes be prefixed with subsystem mnemonic. Thus the user interface employee class might become uiEmployee, and the database employee class might become dbEmployee. This minimizes the risk of globalnamespace collisions.

Many programs have variables that contain computed values: totals, averages, maximums, and so on. If you modify a name with a qualifier like Total, Sum, Average, Max, Min, Record, String, or Pointer, put the modifier at the end of the name. This practice offers several advantages. First, the most significant part of the variable name, the part that gives the variable most of its meaning, is at the front, so it s most prominent and gets read first. Second, by establishing this convention, you avoid the confusion you might create if you were to use both totalRevenue and revenueTotal in the same program. The names are semantically equivalent, and the convention would prevent their being used as if they were different. Third, a set of names like revenueTotal, expenseTotal, revenueAverage, and expenseAverage has a pleasing symmetry. A set of names like totalRevenue, expenseTotal, revenueAverage, and averageExpense doesn t appeal to a sense of order. Finally, the consistency improves readability and eases maintenance. An exception to the rule that computed values go at the end of the name is the customary position of the Num qualifier. Placed at the beginning of a variable name, Num refers to a total. numSales is the total number of sales. Placed at the end of the variable name, Num refers to an index. saleNum is the number of the current sale. The s at the end of numSales is another tip-off about the difference in meaning. But, because using Num so often creates confusion, it s probably best to sidestep the whole issue by using Count or Total to refer to a total number of sales and Index to refer to a specific sale. Thus, salesCount is the total number of sales and salesIndex refers to a specific sale.

Use opposites precisely. Using naming conventions for opposites helps consistency, which helps readability. Pairs like begin/end are easy to understand and remember. Pairs that depart from common-language opposites tend to be hard to remember and are therefore confusing. Here are some common opposites:

For a similar list of opposites in 6 routine names, see Provide 7 services in pairs with their 8 opposites in Section 6.2.

begin/end first/last locked/unlocked min/max next/previous old/new opened/closed visible/invisible source/target source/destination (less common) up/down

In addition to the general considerations in naming data, special considerations come up in the naming of specific kinds of data. This section describes considerations specifically for loop variables, status variables, temporary variables, boolean variables, enumerated types, and named constants.

Guidelines for naming variables in loops have arisen because loops are such a common feature of computer programming. The names i, j, and k are customary:

for ( i = firstItem; i < lastItem; i++ ) { data[ i ] = 0; }

If a variable is to be used outside the loop, it should be given a more meaningful name than i, j, or k. For example, if you are reading records from a file and need to remember how many records you ve read, a more meaningful name like recordCount would be appropriate:

recordCount = 0; while ( moreScores() ) {

score[ recordCount ] = GetNextScore(); recordCount++;

If the loop is longer than a few lines, it s easy to forget what i is supposed to stand for, and you re better off giving the loop index a more meaningful name. Because code is so often changed, expanded, and copied into other programs, many experienced programmers avoid names like i altogether. One common reason loops grow longer is that they re nested. If you have several nested loops, assign longer names to the loop variables to improve readability.