Question

I’m writing a program that uses 1 statement to read 6 floating numbers from user. Then have it print the 6 numbers in 3 lines, with all of following requirements:

(1) the numbers are printed in the reverse order that they are read in

(2) they are on 3 lines: 1 number on the first line, 2 numbers on the next line, 3 numbers on the last line

(3) line up the numbers so they are in column format, right justified, with 1 digit after the decimal point

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Here’s my attempt for the first 2 requirements

#include <stdio.h>

int main(void)

{
    //variable definitions
    float f1,f2,f3,f4,f5,f6;

    printf ("Enter 6 float numbers, separated by commas: ");

    scanf ("%f1,%f2,%f3,%f4,%f5,%f6",&f1,&f2,&f3,&f4,&f5,&f6);

    printf ("%f6\n",f6);
    printf ("%f5,%f4\n",f5,f4);
    printf ("%f3,%f2,%f1\n",f3,f2,f1);

    return 0;

}

To my beginner mind, it makes perfect sense.

Here’s the result when i run it

Enter 6 float numbers, separated by commas: 0.2,3.2,0.1,0.5,0.6,0.7

the numbers are:

-107374176.0000006

-107374176.0000005,-107374176.0000004

-107374176.0000003,-107374176.0000002,0.2000001

Press any key to continue . . .

All of them are garbage outputs except for the last one. Appreciate all the helps!

Answer 1

Your format

scanf ("%f1,%f2,%f3,%f4,%f5,%f6",&f1,&f2,&f3,&f4,&f5,&f6);

expects a 1 after the first float and before the following comma, a 2 after the next etc.

It should be

scanf ("%f,%f,%f,%f,%f,%f",&f1,&f2,&f3,&f4,&f5,&f6);

Since the separating digits weren’t provided, the second conversion (and the following) failed, and the other floats remained uninitialised.