High-level Programming

Abstract

The aim of computer programming is to transform a description of a user’s problem and an approach to its solution into a form whereby it may be executed by a computer. We saw in the first two chapters how a problem may be analysed to derive a clear statement of the program design. In order to achieve the computational objective, the program must be expressed in a precise language, so that it is capable of being transformed—or translated—into a form in which it can be used to control the execution of the target computer. Better still, the program should be suitable for use on many different computers. On the other hand, the program statement should be intelligible to the human reader. This is necessary for two reasons. Firstly, it must be possible to check that the program meets the user’s requirements. In addition, in any practical application, the problem will evolve over a period of time as conditions change. Thus programs inevitably have to be modified to meet the needs of a changing environment. This can be done only if the human programmer who implements the change understands the form and content of the program. High-level programming languages provide facilities for meeting these twin aims. They allow programs to be expressed in a form which is both intelligible to humans and capable of automatic transformation to internal code which may be executed on a computer to achieve the desired end result.