Why when I provide wrong data in fun1 it pass them to func2?

Question

So I have got two functions:

void Fun1() {
    int x, y;
    char term;
    printf("Provide 2 numbers: ");
    if (scanf_s("%d %d%c", &x, &y, &term)<2 || term != '\n') {
        printf("Wrong data.\n");
    }
    else
    {
        if (x > y) {
            printf("Greater number is %d.\n", x);
        }
        else if (x < y) {
            printf("Greater number is %d.\n", y);
        }
        else {
            printf("Numbers are equal.\n");
        }
    }
}

void Fun2() {
    char buf[100];
    printf("Provide your name and surname: ");
    if (fgets(buf, sizeof(buf), stdin) != NULL){
        printf("Hello %s\n", buf);
    }
    else {
        printf("Wrong data\n");
    }
}

I execute one function after another. Why when I provide wrong data in fun1 it pass them to func2? This is simple form of my code with only two functions, but generally I have got four and even when I provide right data in the last function it displays 'Hello ' skipping the part of taking your name and surname.

Provide 2 numbers: 2 a
Wrong data
Provide your name and surname: Hello a

whatever is not used by the scanf is left in the input stream, and then given to fgets as this 2nd function uses the same input stream — B. Go, Mar 01 '20 at 19:55
see https://stackoverflow.com/questions/7898215/how-to-clear-input-buffer-in-c — B. Go, Mar 01 '20 at 20:58
4th line of Fun1 references uninitialized variable `term` leading to random results. — FredK, Mar 01 '20 at 22:04

Why when I provide wrong data in fun1 it pass them to func2?

0 Answers0