Specification (definition of requirements to the program):
At this stage there is a detailed description of the initial data, the requirements to the result are formulated, all possible behavior of the program in special cases are considered (for example, if you entered incorrect data), the dialog windows are developed, which provide the interaction of the user and the program itself.
The development of the algorithm:
At this stage, the programmer determines the sequence of necessary actions, which subsequently must be performed to obtain the desired result.
If there is a situation where the task can be solved in several ways, then of course there are many different variants of the solution algorithm. Then the program developer by some not unimportant criterion (for example, the speed of solving the algorithm) makes a choice of the more appropriate solution.
The result of this stage of program development is a detailed verbal description of the program algorithm, or algorithm flowchart. You can learn more about how to develop an algorithm for any program by studying this article.
Coding:
After the specification and drawing up an algorithm for the solution, the algorithm used will eventually be written in the required programming language (Pascal, Delphi, C++, etc.). The result of the coding stage is the finished program.
Stages of program development. Debugging:
At this stage, the programmer is engaged in debugging the program, that is, looking for and eliminating errors. The latter are divided into two groups: algorithmic and syntactic (errors in the source program text). Syntax errors are the easiest to remove from these two groups, while algorithmic errors are difficult to find.
The debugging stage is considered to be finished only when the source program works correctly and correctly at one or two sets of primary data. What is the compilation of any program and what are the main tasks it performs, you will learn by reading this article.
Testing:
Program testing is very important because in most cases programmers create programs not for personal use, but for others to use their program. During the testing phase, the developer tests the behavior of the program against a large number of sets of input data, both correct and specially selected incorrect ones.
The creation of a reference system:
If a programmer develops a program for others to use later, the programmer needs to develop a help system and establish easy, quick access to that help system for the user when working with the program. Modern programs have help information in the form of CHM or HLP files.
In addition to the help information the help system contains the necessary instructions for installing the program. Usually they are presented as a Readme file in different formats: *.doc, *.txt, *.htm. The step of program development will be described in more detail later.
Stages of program development
Creation of installation disk (CD-ROM):
Developers create an installation disk (CD-ROM) so that users can independently, without the help of a programmer, install this program on their PC.
Typically, in addition to the program itself the installation CD-ROM has help files and instructions for installing the program. It is necessary to notice that the majority of the modern programs, including the programs developed in the environment of Delphi, in many cases, even by simple copying of files cannot be installed on the computer of the user because for correct work of these programs presence of special libraries is necessary and also components which can absent on PC of the concrete user.
For this purpose, a special program recorded on the CD-ROM should install the program on the user’s PC. Usually the installation program creates a separate folder for the program to be installed, then copies the files into this folder, and if necessary configures the operating system by making additions and changes in the registry.