Trying to make a program to take and print the natural log of a number input

[DomBrown2406]

I'm relatively new to C programming and I am trying to make a program to take and print the natural log of a number input by the user but for some reason my program always returns incorrect answers. For example I entered 1 as my number, and the answer came back as some ridiculously big value which is clearly wrong as I know that ln 1 = 0.
My source code is given below, any help would be greatly appreciated :)

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

int main(void)
{
    float in;
    float out;    
    do {
    
    printf("Enter the number to take ln of...\n");
    scanf("%f", &in);
    out = log(in);
    printf("Ln of %f is %f\n", &in, &out);
    printf("If you want to do this again press 1, if not press any other number\n");
    getchar();}
    while(1==1);
}

 

[Borek]

printf("Ln of %f is %f\n", &in, &out);

What & means?

Use [noparse]

[/noparse] tags to format your source code:

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

int main(void)
{
   float in;
   float out; 
   do {
      printf("Enter the number to take ln of...\n");
      scanf("%f", &in);
      out = log(in);
      printf("Ln of %f is %f\n", &in, &out);
      printf("If you want to do this again press 1, if not press any other number\n");
      getchar();
   } while(1==1);
}

 

[DomBrown2406]

The & sign is how my compiler knows what variable i want to use for %f etc.

 

[Borek]

Not exactly. & doesn't mean what variable, & means where the variable is. It is necessary when you use scanf, as scanf needs a reference to be able to put the value in the variable, but printf needs just a value.

 

[DomBrown2406]

Ok, like I said I am relatively new, but I removed those & signs from printf and it works fine now, thanks :)