C Programming - Floating Point Issues - Discussion

Discussion Forum : Floating Point Issues - General Questions (Q.No. 6)
6.
We want to round off x, a float, to an int value, The correct way to do is
y = (int)(x + 0.5)
y = int(x + 0.5)
y = (int)x + 0.5
y = (int)((int)x + 0.5)
Answer: Option
Explanation:

Rounding off a value means replacing it by a nearest value that is approximately equal or smaller or greater to the given number.

y = (int)(x + 0.5); here x is any float value. To roundoff, we have to typecast the value of x by using (int)

Example:


#include <stdio.h>

int main ()
{
  float x = 3.6;
  int y = (int)(x + 0.5);
  printf ("Result = %d\n", y );
  return 0;
}

Output:
Result = 4.

Discussion:
24 comments Page 3 of 3.

Well wisher said:   1 decade ago
Why we should add 0.5 to x :(x+.5)

We can get the answer directly.

y=(int)(x);

I hope this is enough.

In case the round off vale shold not be a min one then we can go for (x+0.5)

Because if u type the above code having x=3.99

Then the roound off value would be 3.

That is not we are looking for.

Vishak said:   1 decade ago
@Ashish: i too thought the same why cant we ? is there a proper explanation ?

Nikhil said:   1 decade ago
Why answer is (int)(x) +0. 5?

Ashish Gupta said:   1 decade ago
We can use both

a) y= int(x+0.5)

b) y= (int)(x+0.5)


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