Scanf_s读取错误的输入

Question

For this code below (in C)

    int small_a, small_b;
    printf("Please input two numbers\n");
    scanf_s("%d %d", &small_a, &small_b);
    printf("%d %d", &small_a, &small_b);
    int test_2nd = small_a - small_b;
    if (test_2nd < 0) {
        printf("a is smaller %d", &small_a);
    }
    else {
    printf("b is smaller %d", &small_b);

The values it prints when I write 4 and 2 is a huge six digit number (5504620 and 5504608 in this case) I don't understand where it goes wrong. stdio.h has been included as a header.

Answer 1

The problem here is in the print statement. In the code

 printf("%d %d", &small_a, &small_b);

you don't need ( want ) to take ( print ) the address. Remove that & .

That said, this actually invokes undefined behavior . %d with printf() expects an argument of type int and you're essentially supplying an int * , causing the UB.

FWIW, to print an address (pointer), you need to use %p format specifier and cast the argument to void *