C++ <cmath> - isnormal() Function

The C++ <cmath> isnormal() function returns true if the given argument is a normal value, else returns false. A normal value is any floating-point value that is neither infinity, NaN, zero or subnormal.

Syntax

C++11

bool isnormal (float x);
bool isnormal (double x);
bool isnormal (long double x);

Parameters

`x`	Specify a floating-point value.

Return Value

Returns true (non-zero value) if the argument is an infinity value, else returns false (zero value).

Example:

The example below shows the usage of isnormal() function.

#include <iostream>
#include <cmath>

using namespace std;
 
int main (){

  cout<<boolalpha;
  cout<<"isnormal(10.5): "<<isnormal(10.5)<<"\n";
  cout<<"isnormal(1.0/0.0): "<<isnormal(1.0/0.0)<<"\n";
  cout<<"isnormal(0.0/0.0): "<<isnormal(0.0/0.0)<<"\n";
  cout<<"isnormal(sqrt(-1.0)): "<<isnormal(sqrt(-1.0))<<"\n";
  return 0;
}

The output of the above code will be:

isnormal(10.5): true
isnormal(1.0/0.0): false
isnormal(0.0/0.0): false
isnormal(sqrt(-1.0)): false

❮ C++ <cmath> Library