sqrt() always returns zero?

contherun · #1 03-May-2008, 23:27

I have tried to calculate the square root of an entered value but it always returns zero.

Here is the code

CPP / C++ / C Code:

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

void main()
{
            int input, lastFactor
            printf("%s", "Enter a number:");
            scanf("%d", &input);

	lastFactor = sqrt(input); //Returns zero all the time
	printf("%d", lastFactor);
	printf("\n");
}

How do I fix this problem?

L7Sqr · #2 04-May-2008, 06:19

I dont know of a sqrt function that takes an int. You may want to view a man page on sqrt. (Hint: floating point numbers)
Also, are you checking the number being passed to sqrt? Are you sure input was entered correctly? scanf returns a value, you should see what that indicates and what you get.

davekw7x · #3 04-May-2008, 07:42

Quote:

Originally Posted by contherun

tried to calculate...
how do i fix this problem please help????

1. The code that you posted won't compile because there is no semicolon at the end line number 6. For best chances of helpful responses with minimum iterations, I respectfully suggest that you make sure to show us exactly what you are working on. You might also mention what compiler you are using. Sometimes it makes a difference to people who are trying to help.

2. After I installed the missing semicolon, my compiler rejects the code because it insists that the main() function be declared with an int return type. Some compilers are happy with void main(), but it is not standard usage. This is not a "Big Deal" with me personally, but I just thought that while you are learning, you might want to learn standard ways of doing things.

3. The program gives the correct square root of an integer, but if there is a fractional part, it is truncated, since you are using integer variables.

4. When you submit a question like this, it is a good idea to give us some details. (What input you gave it; what output it gave you; what you expected. Stuff like that.)

So for example, if you see something like

Code:

Enter a number:123
11

That's normal.

So is

Code:

Enter a number:0.123
0

Now, if you really had something in mind like

Code:

Enter a number:123
11.090536

or

Code:

Enter a number:0.123
0.350714

Then change your variable declarations to make their type be float, instead of int

Regards,

Dave

davekw7x · #4 04-May-2008, 12:47

Quote:

Originally Posted by davekw7x

Then change your variable declarations to make their type be float, instead of int

And, of course, use %f instead of %d format specifiers in scanf() and printf() statememts.

Regards,

Dave

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sqrt() always returns zero?

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