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Definition and use of namespaces
Namespaces example from a Well House Consultants training course
More on Namespaces [link]
Source code: Ns.cpp Module: C237
#include <iostream>
/* Namespaces in C++ allow you to subdivide your variable space into a series of areas, thus providing you with the ability to bring in a whole lot of variables as a "clump" or group to your program. The std namespace includes objects such as cin, cout, cerr, endl, exception - and many more - and is often imported in full. */ // Define two namespaces and their variables namespace platypus { int feet; int heads; } namespace zaphod { int feet; int heads; } /* could also do using namespace std; rather than std::cout BUT that might clutter your default namespace. So if you just want one or two or have LOTS of namespaces, best to do it the way I have below. using std::cout; Or even cherry picking as in the actual code below */ // This example also show you how to call a C function from C++: extern "C" int avg(int, int); int main () { platypus::feet = 4; zaphod::feet = 2; platypus::heads = 1; zaphod::heads = 2; std::cout << "Heads " << platypus::heads << " feet " <<platypus::feet << std::endl; std::cout << "Heads " << zaphod::heads << " feet " <<zaphod::feet << std::endl; int num = avg(8, 24); std::cout << num << std::endl; } /* Output: 92:antrim graham$ ./Ns Heads 1 feet 4 Heads 2 feet 2 16 92:antrim graham$ */ Learn about this subject
This module and example are covered on the following public courses:
* Learning to program in C and C++ * C++ for C Programmers * C and C++ Programming * Learning to program in C and C++ * C and C++ Programming Also available on on site courses for larger groups Books covering this topic
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Other Examples
This example comes from our "Namespaces" training module. You'll find a description of the topic and some
other closely related examples on the "Namespaces" module index page.
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