A RetroSearch Logo

Home - News ( United States | United Kingdom | Italy | Germany ) - Football scores

Search Query:

Showing content from https://en.cppreference.com/w/cpp/language/../error/../language/../utility/variadic.html below:

Variadic functions - cppreference.com

Variadic functions are functions (e.g. std::printf) which take a variable number of arguments.

To declare a variadic function, an ellipsis appears after the list of parameters, e.g. int printf(const char* format...);, which may be preceded by an optional comma. See Variadic arguments for additional detail on the syntax, automatic argument conversions and the alternatives.

To access the variadic arguments from the function body, the following library facilities are provided:

[edit] Example
#include <cstdarg>
#include <iostream>
 
void simple_printf(const char* fmt...) // C-style "const char* fmt, ..." is also valid
{
    va_list args;
    va_start(args, fmt);
 
    while (*fmt != '\0')
    {
        if (*fmt == 'd')
        {
            int i = va_arg(args, int);
            std::cout << i << '\n';
        }
        else if (*fmt == 'c')
        {
            // note automatic conversion to integral type
            int c = va_arg(args, int);
            std::cout << static_cast<char>(c) << '\n';
        }
        else if (*fmt == 'f')
        {
            double d = va_arg(args, double);
            std::cout << d << '\n';
        }
        ++fmt;
    }
 
    va_end(args);
}
 
int main()
{
    simple_printf("dcff", 3, 'a', 1.999, 42.5); 
}

Output:

[edit] See also

RetroSearch is an open source project built by @garambo | Open a GitHub Issue

Search and Browse the WWW like it's 1997 | Search results from DuckDuckGo

HTML: 3.2 | Encoding: UTF-8 | Version: 0.7.4