One of the benefits of Access from a developer’s perspective is its relative compatibility with the structured query language (SQL). It is very fast, reliable and is very dependable when it comes to rapid application development. Microsoft Access is primarily used for developing standalone applications. This is used to test the typecast using “as”. The “is” operator allows the user to compare the instances of the object to a class. This also allows one type to be changed to another type and it shows an error if the type is not compatible with the system. The “as” operator is a protected typecast that allows the compiler to treat one object at a time. The operators are needed to have the information at runtime. The operators that is being used for RTTI are “as” and “is”. The net result is the ability to create more abstract and generalized frameworks that can operate on any type that exposes RTTI. Using the functionality provided in the System.Rtti unit, you can obtain this information at run time. If RTTI generation is enabled, the resulting binary includes special metadata that contains information about types (for example, class ancestry, declared fields, annotated attributes). RTTI: Run-time type information (RTTI) is a programming paradigm in which information about a type can be obtained at run time. But there is a down side to this automation that is often overlooked, especially by newcomers, giving rise to memory leaks. When you create an object, Delphi handles the memory allocation for the object as you call the Create method of the object class. It has allowed complex code to be written in nicely encapsulated modules (objects). Object Orientation has transformed the process of application development. Objects also allowed events, such as mouse clicks, to be handled neatly – a button object could call a routine (method) of another object when clicked. And the object could be asked to sort the list into sequence. For example, a list object could have items added or removed from the list at will. You did not need to furnish the internal data since it was retained across calls. You called an object to do something and left the object to sort out how it did it. Now they retained their data, and were in fact, collections of routines under one umbrella. It took the concept of subroutines into a completely different zone. Object orientation radically changed the face of programming for many people. Use it with care, or you will end up addressing the wrong memory. The Pointer type is a dangerous one – it falls foul of Delphi’s normally tight type handling. Incrementing a PInt64 pointer will add Size of (Int64) bytes to the pointer address so that it points to the next Int64 variable in memory. The nice thing about the typed pointers is that they work sensibly with the Inc and Dec functions. When calling Windows APIs (Application Programmer Interfaces), we are obliged to use pointers.ĭelphi provides a number of typed pointer types, such as PChar, and PExtended, along with a generic, ‘point to anything’ type – the Pointer type. You would then use the pointer just as if it were a record variable. You might use a record pointer, for example, to point to a block of memory where you have stored lots of record data. They can point to other variables, or to memory. Pointer is a variable that holds the address of anything in memory. How does Delphi handle Windows callbacks? Support community on the Internet is very much. Support additional component that is very much on the Internet, even for a freeware category with the same quality or better than commercial components. It was the closest you could get to the RAD (Rapid Application Development) concept at the time.Ī structured programming language and syntax are clear, so easy to read, studied and understood. Ī then-revolutionary IDE which allowed to implement GUIs by drag & drop, making it easy to draw a nice UI, add event handlers, and test it in real time. Especially the early 2001’s interface (GUI) it’s easier than VB Delphi let alone VC++. Some of the coursework must create a program with a good interface, because the basic know pascal the first “forced” to make with Delphi. In the early days in college, there are basic programming courses and programming language used was Pascal, so from then on was known programming pascal.Ī very clear syntax, leading to readable code.
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