isnormal Function in C++ Programming

In this article we will be discussing the working, syntax and examples of isnormal() function in C++ STL.

Isnormal() is a function which comes under the <cmath> header file. This function is used to check whether the given number is a normal number or not.

What is a normal number?

A real number is known as a normal number if its base a number is neither zero, infinity, NAN or subnormal.

Syntax

bool isnormal(float num);

Parameters

The function accepts only one parameter which is num, of float type.

Return value

It returns 0 or 1, if the number is a normal number then the function returns 1 else 0.

Example

Input: isnormal(5.0);
Output: 1

Input: isnormal(0.0);
Output: 0

Example

 Live Demo

#include <bits/stdc++.h>
using namespace std;
int main() {
   //For Float
   cout<<"\n For Float : ";
   float var_1 = 5.89F;
   //when value is other than zero
   cout<<"check for isnormal(5.89F) : "<<isnormal(var_1);
   //when value is zero
   var_1 = 0.0F;
   cout<<"\ncheck for isnormal(0.0F) : "<<isnormal(var_1);
   //when its a infinite value by dividing it with 0.0
   var_1 = 2.2F;
   cout<<"\ncheck for isnormal(2.2F/0.0F) : "<<isnormal(var_1/0.0F);
   //For double
   cout<<"\n\n For Double : ";
   double var_2 = 5.89;
   //when value is other than zero
   cout<<"check for isnormal(5.89) : "<<isnormal(var_2);
   //when value is zero
   var_2 = 0.0;
   cout<<"\ncheck for isnormal(0.0) : "<<isnormal(var_2);
   //when its a infinite value by dividing it with 0.0
   var_2 = 2.2;
   cout<<"\ncheck for isnormal(2.2/0.0) : "<<isnormal(var_2/0.0);
   //For Long double
   cout<<"\n\n For Long Double : ";
   long double var_3 = 5.89;
   //when value is other than zero
   cout<<"check for isnormal(5.89) : "<<isnormal(var_3);
   //when value is zero
   var_3 = 0.0;
   cout<<"\ncheck for isnormal(0.0) : "<<isnormal(var_3);
   //when its a infinite value by dividing it with 0.0
   var_3 = 2.2;
   cout<<"\ncheck for isnormal(2.2/0.0) : "<<isnormal(var_3/0.0);
   return 0;
}

Output

If we run the above code it will generate the following output −

For Float :
check for isnormal(5.89F) : 1
check for isnormal(0.0F) : 0
check for isnormal(2.2F/0.0F) : 0
For Double :
check for isnormal(5.89) : 1
check for isnormal(0.0) : 0
check for isnormal(2.2/0.0) : 0
For Long Double :
check for isnormal(5.89) : 1
check for isnormal(0.0) : 0
check for isnormal(2.2/0.0) : 0