Here's a sample exercise from the C course ... set yesterday to tailor the course for the particular group of delegates that we have this week:

---

/* Complete my program ...
... in 2 files
... fixed VAT rate at compile time
 
Function params - cost per item (net) and
no. of items at this cost
 
tc is gross.
 
*/
 
 
items = 0;
tc = 0.0
tc += vatable(17.6,2);
tc += vatable(18.4,4);
tc += vatfree(19.5,3);
 
printf ("............", items, tc);

---

You'll work out from the pseudocode that items needs to be a global variable - and that really the vatable and vatfree functions should be in a separate file. That brings function templates and extern into play in the example.

Solution - source code of main file [here] and of the the functions [here].

The compile line to build the application under gcc would be as follows:
  gcc -o xrcz xrcz.c taxi.c
or to separate out the compiles:
  gcc -c taxi.c
  gcc -c xrcz.c
  gcc -o xrcz xrcz.o taxi.o
(written 2010-06-30)

 C204 - C and C based languages - Functions, Macros and programs in multiple files
  [775] Do not duplicate your code - (2006-06-23)
  [1163] A better alternative to cutting and pasting code - (2007-04-26)
  [1478] Some new C programming examples - files, structs, unions etc - (2007-12-19)
  [2570] Function Prototypes in C - (2010-01-11)
  [2575] Sharing variables between files of code in C - extern - (2010-01-14)
  [3237] Using functions to keep look and feel apart from calculations - simple C example - (2011-04-09)
  [3717] Returning extra results from a function in C - (2012-05-03)
  [3721] Naming blocks of code, structures and Object Orientation - efficient coding in manageable chunks - (2012-05-06)
  [4338] Passing arrays into functions in C - (2014-12-02)
  [4554] Passing information into functions in C - by name, by value - (2015-10-26)
  [4555] Preprocessor directives in C and C++ - what they mean - (2015-10-27)
  [4557] Function prototype - what they are and why you should use them - C and C++ - (2015-10-27)

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Forward to Staring a C course with Hello World - why?

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Learning about Regular Expressions in C through examples
String functions in C
Staring a C course with Hello World - why?
C Course exercise and sample answer - source in 2 files
Just pass a pointer - do not duplicate the data
Software versions used - June 2010
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