了解size_t类型和sizeof运算符的问题

Question

void sizeof_test2();

void sizeof_test2()
{
    int array[5];
    size_t arr_size = sizeof(array);

    printf( "sizeof:\n"
            "array = %d\n"
            "arr_size = %d\n", sizeof(array), sizeof(arr_size));
}

GCC编译器输出:

sizeof_test2.c: In function `sizeof_test2':  
sizeof_test2.c:6: error: `size_t' undeclared (first use in this function)  
sizeof_test2.c:6: error: (Each undeclared identifier is<br>
reported only once sizeof_test2.c:6: error: for each function it<br>
appears in.) sizeof_test2.c:6: error: parse error before "arr_size"<br>
sizeof_test2.c:10: error: `arr_size' undeclared (first use in this<br>
function) make[2]:  [build/Debug/Cygwin-Windows/sizeof_test2.o]<br>
Error 1 make[1]:  [.build-conf] Error 2<br>  

不知道为什么我收到这个错误,通过显示size_t类型的正确方法是printf什么？

Answer 1

size_ttype在stddef.hheader(和其他头文件stdio.h)中定义.

请注意,在您的程序中,您正在使用printf功能,因此您必须包括stdio.h.