Delphi 3 Review

Remember Delphi 3? Me neither, but here's a copy of my Long Term Test of Delphi 3 that appeared in January 1998's edition of Personal Computer World.

Delphi is a visual programming language, competing directly with Visual Basic. I’ve been using Delphi since version 1 and have been using Delphi 3 for the past six months.

Delphi 3 and Visual Basic 5 have very similar features, but in my opinion Delphi has one great advantage for programmers trying to write reusable, maintainable code. It is object-oriented (OO) and has been built from the ground up as an OO tool, not merely as an afterthought.

The Visual Component Library (VCL) encapsulates all the Windows controls in easy to use components. However, Borland has been quite poor at encapsulating some of the Windows 95 controls such as the Rich Edit and List View controls. But, if a VCL component doesn’t contain some of the functionality you require, it’s simple to derive your own component, add the functionality you require and install it back into the Component Palette.

Another OO feature that initially seemed to be a bit of a gimmick is form inheritance. Now, after using this feature, I’ve realised how useful this can be. For example, I have a dialog box form from which every other dialog box is derived from. Now, if I’d like to make a foreign language version of my software, I’ll need to change the wording on the ‘OK’ and ‘Cancel’ buttons. With form inheritance, I can just change the wording in the base dialog box form and that’s it. A bit easier than changing it in 20 to 30 places, don’t you think?

Also gimmicky but useful is the "Code Complete" feature. Type in the name of an object and a list of its properties and methods will appear. Click one of the methods and tool tip will show the parameters taken by the method. This saves traipsing through the help files, which have been notoriously bad since release 1 and have not improved tremendously.

Delphi comes with a native code compiler, which must be the fastest compiler of any development tool. This means, for simple projects, all you need to ship is the EXE file. However, if you require database support, you’ll need to ship the Borland Database Engine. The code produced does seem to be quite large, compared to that produced by products such as Visual C++.

On the downside, Delphi 3 does seem to be a little less stable than its predecessors are. Often, after a bug has occurred, it’s necessary to leave Delphi and come back in again. Fortunately, I haven’t lost any of my code yet.

Overall, I continue to be hugely impressed by Delphi. I can’t think of one example where I have been unable to achieve something because of the limitations of the tool. It usually comes down to me being stupid or Windows preventing me from doing what I want to do. Some people are of the opinion that Delphi is harder to learn than VB, but I don’t know if this true. If you’re likely to be coding from within Word, Excel etc., then using VB as your sole programming language may make sense.

Delphi comes in three flavours – Developer, Professional and Client/Server. Unless finances are stretched, I would recommend purchasing the Professional version, which provides the source code for the VCL. This is an invaluable resource, for tracing through to find bugs and also to pick up coding tips. All the versions also come with a free copy of Delphi 1, which means you can continue to develop 16-bit software, if required.

If you’re put off by the thought of Pascal, there is always C++ Builder, which is almost exactly the same as Delphi but uses C++ as its language.

In terms of what PC you’ll need to run Delphi, I would recommend a Pentium with at least 16MB of RAM.

Good Points

Object-orientated programming, the fastest compiler I've seen.

Bad points

Help files are poor.


Still the best visual programming tool on the market. Possibly consider VB if you're going to be writing code in Office applications as well.