In Standard C and C++, the address of the first element past the end of an array can be used in pointer arithmetic. Thus, you can initialize a vector with the contents of a built-in array, like this: int arr[3] = {1, 2, 3}; vector vi ( arr, //address of
The Standard defines a side effect as a change in the state of the execution environment. Modifying an object, accessing a volatile object, invoking a library I/O function, or calling a function that does any of these operations are all side effects.
A common mistake is to initialize static class members inside the constructor body or a member-initialization list like this: class File{ private: static bool locked; private: File(); //
One of the most frustrating aspects of debugging is detecting memory overruns. Some compilers (MS Visual C++ for instance) automatically add “sentry bytes” at the ends of every memory block allocated by operator new. The sentry bytes have a predefined value that the runtime system monitors. When the predefined value
The conditional operator,?, is a shorthand for a sequence of if-else statements. Although it has legitimate uses, in many cases programmers tend to misuse it, thereby producing unintelligible and buggy code. Sometimes, the use of the conditional operator yields undefined behavior. Consider this example: int n = 1; n =
When you’re working with QueryDef (SQL instructions stored on an MDB database) and open it, DAO loads all the QueryDefs. For example, if you have an MDB with five QueryDefs named qryCustomers, qryOrders, qryContacts, qrySales, and qryPersons, and you want to use the qryCustomers, do this: Dim qdCustomer as QueryDefDim
These several database functions work together and perform various utility functions, such as checking if fields and tables exist, creating fields and tables, and so on. The interface hides all the code and returns True or False to report the status of the functions: Function CreateDatabase(DatabasePath As String, dbLanguage _
For simple Microsoft Access security, set the database password from the Security item under the Tools menu in Access, select Set Database Password, and enter a password. To use the database in VB, pass a value along with the “pwd” keyword to the SOURCE value of the OpenDatabase method: Dim
This code helps test SQL functions or other string-manipulation routines so you can generate random strings. You can generate random-length strings with random characters and set ASCII bounds, both upper and lower: Public Function RandomString(iLowerBoundAscii As _ Integer, iUpperBoundAscii As Integer, _ lLowerBoundLength As Long, _ lUpperBoundLength As Long) As