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C Programming - Floating Point Issues

Exercise : Floating Point Issues - General Questions
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.

7.
The binary equivalent of 5.375 is
101.101110111
101.011
101011
None of above
Answer: Option
Explanation:
No answer description is available. Let's discuss.
8.
A float occupies 4 bytes. If the hexadecimal equivalent of these 4 bytes are A, B, C and D, then when this float is stored in memory in which of the following order do these bytes gets stored?
ABCD
DCBA
0xABCD
Depends on big endian or little endian architecture
Answer: Option
Explanation:
No answer description is available. Let's discuss.
9.
What will you do to treat the constant 3.14 as a float?
use float(3.14f)
use 3.14f
use f(3.14)
use (f)(3.14)
Answer: Option
Explanation:

Given 3.14 is a double constant.
To specify 3.14 as float, we have to add f to the 3.14. (i.e 3.14f)

10.
Which of the following statement obtains the remainder on dividing 5.5 by 1.3 ?
rem = (5.5 % 1.3)
rem = modf(5.5, 1.3)
rem = fmod(5.5, 1.3)
Error: we can't divide
Answer: Option
Explanation:

fmod(x,y) - Calculates x modulo y, the remainder of x/y.
This function is the same as the modulus operator. But fmod() performs floating point divisions.

Example:


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

int main ()
{
  printf ("fmod of 5.5 by 1.3 is %lf\n", fmod (5.5, 1.3) );
  return 0;
}

Output:
fmod of 5.5 by 1.3 is 0.300000

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