使用 scanf 时出错：返回值被浮点忽略

Question

this is my code and I'm not sure why I'm getting an error whenever I try to test it. It keeps saying return value ignored with scanf

#include <stdio.h>
#include <math.h>


int main(void) {

    float money, tax, result;

    printf("Enter the amount of money.");
    scanf("%f", &money);

    tax = 0.05 * money;

    result = tax + money;

    printf("With tax added: $%f", result);

    return 0;
}

Answer 1

It is because return value is ignored.

You should check return values of scanf() to check if readings are successful.

#include <stdio.h>
#include <math.h>


int main(void) {

    float money, tax, result;

    printf("Enter the amount of money.");
    if (scanf("%f", &money) != 1) {
        fputs("read error!\n", stderr);
        return 1;
    }

    tax = 0.05 * money;

    result = tax + money;

    printf("With tax added: $%f", result);

    return 0;
}