c++ printf函数的应用场景与案例分析

C++??printf????C???????,??????????C++?,??printf??,?????????????????std::cout,???????,printf????????????

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1. ?C???:???C++??C????,??C??????????,???????printf?
2. ??????:????????????,printf???std::cout??,??????????,???????????????
3. ??????:??????????????????,printf???????????
4. ????:??????,printf?????????????????????

????

??1:????

#include
#include 

int main() {
    int a = 10;
    double b = 3.14;
    const char* s = "Hello, World!";
    
    // ??printf??
    std::printf("a = %d, b = %f, s = %s\n", a, b, s);
    
    return 0;
}

??2:??????

#include
#include 

int main() {
    int year = 2023;
    int month = 9;
    int day = 15;
    
    // ??printf??????
    char date[20];
    std::snprintf(date, sizeof(date), "%d-d-d", year, month, day);
    
    std::cout << "Formatted date: "<< date<< std::endl;
    
    return 0;
}

??3:?C???

#include
#include 
#include 

// ??????C???,???????
extern "C" void print_formatted(const char* format, ...) {
    va_list args;
    va_start(args, format);
    vprintf(format, args);
    va_end(args);
}

int main() {
    int x = 10;
    int y = 20;
    
    // ??C???,??printf???????
    print_formatted("x = %d, y = %d\n", x, y);
    
    return 0;
}

??????,print_formatted???C???,???????????C++??C???????,???????C++???va_list?va_start?va_end?????,??????vprintf??,??????????

????,???C++???????std::cout????,????????,printf?????????????C??????????????????????????,printf???????????