Procedures and Functions

The next step along the path of abstraction was the development of procedures and functions. Libraries of procedures, such as mathematical libraries, or input/output libraries, provided the first hints of information hiding. These libraries raised the level of abstraction, they permitted the programmer to think about operations in high level terms, concentrating on the task to be done, the what, and not on the implementation, the how.

while these were an important step, they were not an entirely effective mechanism of information hiding, as we will explain in the next slide.

[audio] [real] Text to accompany slide23, in Chapter 2 of An Introduction to Object-Oriented Programming