Storage Classes

Abstract

Most large programs are written by teams of programmers. After they design the general outline of the program together, each programmer goes off and writes an isolated piece of the program. When everyone is finished, all the pieces are linked together to form the complete program. For this process to work, there must be a mechanism to ensure that variables declared by one programmer don’t conflict with unrelated variables of the same name declared by another programmer. On the other hand, there is usually some data that needs to be shared between different source files, so there must also be a mechanism that ensures that some variables declared in different files do refer to the same memory locations and that the computer interprets those locations in a consistent fashion. In C, you define whether a variable is to be shared, and which portions of code can share it, by designating its scope.

Memory: what wonders it performs in preserving and storing up things gone by, or rather, things that are!

Plutarch, Morals: On the Cessation of Oracles