Generating wrappers for a variable length argument function presents a number of special challenges. Although C provides support for implementing functions that receive variable length arguments, there are no functions that can go in the other direction. Specifically, you can't write a function that ...
int i; /* initialize valist for num number of arguments */ va_start(valist, num); /* access all the arguments assigned to valist */ for (i = 0; i < num; i++) { sum += va_arg(valist, int); } /* clean memory reserved for valist */ va_end(valist); return sum/num; ...
(4, 12.2, 23.3, 33.3, 12.1); or you could write avg(2, 2.3, 34.4); The advantage of this approach is that it's much easier to change the code if you want to change the number of arguments. Indeed, some library functions can accept a variable list of arguments (such as printf--...
The function call can provide more arguments than the number of argument variables defined in the function statement. You can pass arguments to a function that has no argument variable defined. To help us understand how use variable-length argument list feature, I wrote this tutorial example: ...
Variable length codes are useful for data compression. However, a variable length code would be useless if the codewords could not be identified in a unique way from the encoded message. Example 2.2 Consider the variable length code (0, 10, 010, 101) for alphabet (A, B, C, D). A se...
15. Variable-Length Argument Lists15.1 I heard that you have to #include <stdio.h> before calling printf. Why? 15.2 How can %f be used for both float and double arguments in printf? Aren't they different types? 15.3 I had a frustrating problem which turned out to be caused by the...
( double d in numbers ) 14 total += d; 15 16 return total / numbers.Length; 17 } // end method Average 18 19 public static void Main( string[] args ) 20 { 21 double d1 = 10.0; 22 double d2 = 20.0; 23 double d3 = 30.0; 24 double d4 = 40.0; 25 26 Console.WriteLine(...
In this article, we won't go into printf-like parsing of a format string. Instead, let's start with the simplest variation: The following function accepts a variable number of positive integer arguments, and returns the integer average. To signal the end of the variable-length argument list...
> + if (length != move_page_tables_up(vma, old_start, > + vma, new_start, length)) > + return -ENOMEM; > + > + lru_add_drain(); > + tlb = tlb_gather_mmu(mm, 0); > + free_pgd_range(&tlb, old_start, new_start, ...
Variable-Size Arrays in C Dennis M. Ritchie Bell Laboratories Murray Hill, NJ, USA [This is a version of a paper published in Journal of C Language Translation, vol 2 number 2, September 1990.] Both the original C language and ANSI C handle vectors of indefinite length, but neither ...