Minor Coding error

[marmar12]

#include<stdio.h>

#define SHIP_COST 7.00
#define FREE_SHIP_LIMIT 25.00

main ()
{
float BP = 0;
float numBooks=0;
float Avg = 0;
float Total = 0;


while (BP != -1)
{
printf("please enter the price of book: %d", BP);
scanf("%d", &BP);

Total += BP * 1.05;
numBooks++;
}

Avg= Total/numBooks;
printf("the average is %f", Avg);
printf("The total price is %f", Total);
}


given my code, when i compile it, i get a very very weird output. it'll print out the first printf but with a 0 infront of it. Also, when i run the code and enter "-1" the loop doesnt end and sometimes, it infinitely prints out" please enter the price of book" Please help as much as possible. I've never had this problem before.

[Meetee]

#include<stdio.h>

#define SHIP_COST 7.00
#define FREE_SHIP_LIMIT 25.00

main ()
{
float BP = 0;
float numBooks=0;
float Avg = 0;
float Total = 0;


while (BP != -1)
{
printf("please enter the price of book: %d", BP);
scanf("%d", &BP);

Total += BP * 1.05;
numBooks++;
}

Avg= Total/numBooks;
printf("the average is %f", Avg);
printf("The total price is %f", Total);
}

In bold there are few errors which are really minor but create big issues if not recovered!! float xyz should be initialized to 0.0 (float xyz = 0.0) and while in printf and scanf you need to write %f instead of %d so correct them.

Regards

[weaknessforcats]

float xyz should be initialized to 0.0 (float xyz = 0.0)

.

Almost correct. 0.0 is a double. A float should be initialized using 0.0f.

float xyz = 0.0f;
float abc = 0.0F;
 

Also:

while (BP != -1)

will not work as you desire. Not even using -1.0F.

Generally, you cannot use operators like ==, !=, >, <, <=, >=, etc wth floating point numbers.
Due to the automatic rounding, these operators may report a condition as true when the numbers
are only close in value.

Google for Floating Point Arithmetic or read IEEE 754 standard specification for details.

To compare two floating point numbers, you have to establish a sigma error tolerance.

if (fabs(i - j) < 0.000001) { ... // almost equal }