312 Object-Based Programming Chapter 8 (Web site builder) Fig. 8.12 Fig.
312 Object-Based Programming Chapter 8 Fig. 8.12 Fig. 8.12Fig. 8.FiFi12g. 8.12g. 8.12thisreference demonstration. (Part 2 of 2.) Unlike C and C++, in which programmers must manage memory explicitly, C# performs memory management internally. The .NET Framework performs garbage collection of memory to return to the system memory that is no longer needed. When the garbage collector executes, it locates objects for which the application has no references. Such objects can be collected at that time or during a subsequent execution of the garbage collector. Therefore, the memory leaks that are common in such languages as C and C++, where memory is not reclaimed automatically, are rare in C#. Allocation and deallocation of other resources, such as network connections, database connections and files, must be handled explicitly by the programmer. One technique employed to handle these resources (in conjunction with the garbage collector) is to define a destructor (sometimes known as a finalizer) that returns resources to the system. The garbage collector calls an object s destructor to perform termination housekeeping on that object just before the garbage collector reclaims the object s memory (called finalization). Each class can contain only one destructor. The name of a destructor is formed by preceding the class name with a ~character. For example, the destructor for class Timewould be ~Time(). Destructors do not receive arguments, so destructors cannot be overloaded. When the garbage collector is removing an object from memory, the garbage collector first invokes that object s destructor to clean up resources used by the class. However, we cannot determine exactly when the destructor is called, because we cannot determine exactly when garbage collection occurs. At program termination, any objects that have not been not garbage collected previously will receive destructor calls. 8.11 staticClass Members Each object of a class has its own copy of all the instance variables of the class. However, in certain cases, all class objects should share only one copy of a particular variable. Such variables are called static variables. A program contains only one copy of each of a class s staticvariables in memory, no matter how many objects of the class have been instantiated. A staticvariable represents class-wide information all class objects share the same staticdata item. The declaration of a staticmember begins with the keyword static. A static variable can be initialized in its declaration by following the variable name with an =and an initial value. In cases where a static variable requires more complex initialization, programmers can define a static constructor to initialize only the static members. Such constructors are optional and must be declared with the statickeyword, followed by the name of the class. staticconstructors are called before any staticmembers are used and before any class objects are instantiated.
From our experience, we can recommend PHP Web Hosting services, if you need affordable webhost to host and run your web application.