Static Duration, Internal Linkage

• A variable with internal linkage is local to the file containing it. (It cannot be used in another file).

• A variable with external linkage can be used in different files.

• (of course, for external linkage, only one file can contain the definition, all the others must be references.)

• See example in Figure 9.4

• Practice: twofile1.cpp and twofile2.cpp (TwoMakefile example)