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| <p> |
| Previous: <a rel="previous" accesskey="p" href="How-Variadic.html#How-Variadic">How Variadic</a>, |
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| <h4 class="subsection">A.2.3 Example of a Variadic Function</h4> |
| |
| <p>Here is a complete sample function that accepts a variable number of |
| arguments. The first argument to the function is the count of remaining |
| arguments, which are added up and the result returned. While trivial, |
| this function is sufficient to illustrate how to use the variable |
| arguments facility. |
| |
| <!-- Yes, this example has been tested. --> |
| <pre class="smallexample"> #include <stdarg.h> |
| #include <stdio.h> |
| |
| int |
| add_em_up (int count,...) |
| { |
| va_list ap; |
| int i, sum; |
| |
| va_start (ap, count); /* <span class="roman">Initialize the argument list.</span> */ |
| |
| sum = 0; |
| for (i = 0; i < count; i++) |
| sum += va_arg (ap, int); /* <span class="roman">Get the next argument value.</span> */ |
| |
| va_end (ap); /* <span class="roman">Clean up.</span> */ |
| return sum; |
| } |
| |
| int |
| main (void) |
| { |
| /* <span class="roman">This call prints 16.</span> */ |
| printf ("%d\n", add_em_up (3, 5, 5, 6)); |
| |
| /* <span class="roman">This call prints 55.</span> */ |
| printf ("%d\n", add_em_up (10, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10)); |
| |
| return 0; |
| } |
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