C程序：编写了将int转换为float的代码，但这给了我0.0000，并将我的输入更改为一些奇怪的数字

Question

I have the following piece of code, also available at this link .

#include <stdio.h>
int main()
{
    int n;
    printf("\nPlease input an integer to convert to float: %d", n );
    scanf("%d", &n);
    printf("\nYour float is: %.5f", n);

    return(0);

}

What it's doing is not converting the float, it only gives me 0.0000, and it also takes my input and makes it some wacky number. I'm not sure what I'm doing wrong, even after looking around on different sites. I can't use any library, either, so nothing of atol, etc

Answer 1

#include <stdio.h>

int main() {
    int n;
    printf("\nPlease input an integer to convert to float: ");
    scanf("%d", &n);
    printf("\nYour float is: %.5f", (float)n);

    return(0);
}

You have to explicitly write the cast, if you want an integer to be converted to a float in that way. If you don't, this causes undefined behavior. Another way is to declare a float variable and assign n to it.

By the way, the code you wrote shouldn't even compile without a warning on GCC.