The fpclassify() function are defined in header math.h header in C and cmath library in C++. This function is used to get the value of type int that matches one of the classification macro constants (depending on the value of x).
Syntax:
int fpclassify(int x); int fpclassify(float x); int fpclassify(double x); int fpclassify(long double x);
Parameters: This method accepts a parameter x which is the value to be matched with one of the macro constants of this method. It can be integer, float, double or long double.
Return Value: This function returns integer values for the macro constants as follows:
- FP_INFINITE: When the specified value is Positive or negative infinity
- FP_NAN: When the specified value is not a Number
- FP_ZERO: When the specified value is a zero.
- FP_SUBNORMAL: When the specified value is a positive or negative denormalized value
- FP_NORMAL: When the specified value is a positive or negative normalized non-zero value
Below example demonstrate the use of fpclassify() method:
// C++ program to demonstrate // the use of fpclassify() method #include <iostream> #include <math.h> using namespace std;
// Function to implement fpclassify() method void fpclassification( double x)
{ // fpclassify() method
switch (fpclassify(x)) {
// For the data to be infinite
case FP_INFINITE:
cout << "Infinite Number \n" ;
break ;
// For the data to be not defined
// as in divide by zero
case FP_NAN:
cout << "Not a Number \n" ;
break ;
// For the data to be zero
case FP_ZERO:
cout << "Zero \n" ;
break ;
// For the data to be subnormal
case FP_SUBNORMAL:
cout << "Subnormal value \n" ;
break ;
// For the data to be normal
case FP_NORMAL:
cout << "Normal value \n" ;
break ;
// For the data to be invalid
default :
cout << "Invalid number \n" ;
}
} // Driver code int main()
{ // Example 1
double a = 1.0 / 0.0;
cout << "For 1.0/0.0: " ;
fpclassification(a);
// Example 2
double b = 0.0 / 0.0;
cout << "For 0.0/0.0: " ;
fpclassification(b);
// Example 3
double c = -0.0;
cout << "For -0.0: " ;
fpclassification(c);
// Example 4
double d = 1.0;
cout << "For 1.0: " ;
fpclassification(d);
return 0;
} |
Output:
For 1.0/0.0: Infinite Number For 0.0/0.0: Not a Number For -0.0: Zero For 1.0: Normal value