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isnormal() in C++
• Last Updated : 27 Sep, 2018

This function is defined in <cmath.h> . By using isnormal() function, we determines that whether the given number is normal (neither zero, infinite nor NAN) or not. This function returns 1 if the number is normal else return zero.

Syntax:

`bool  isnormal(float x);`

or

`bool  isnormal(double x); `

or

`bool  isnormal(long double x); `

Parameters: This functions takes a mandatory parameter x which represents the floating point value.

Returns: If the given value is normal then the function returns 1 otherwise the function returns zero.

Below program illustrate the isnormal() function in C++:

Example 1:- To show with float value

 `// c++ program to demonstrate``// example of isnormal() function.`` ` `#include `` ` `using` `namespace` `std;`` ` `int` `main()``{`` ` `    ``float` `f = 7.0F;`` ` `    ``// check for non-zero value``    ``cout << ``"isnormal(7.0) is = "` `<< isnormal(f) << endl;`` ` `    ``// check for zero``    ``f = 0.0F;``    ``cout << ``"isnormal(0.0) is = "` `<< isnormal(f) << endl;`` ` `    ``// check for infinite value``    ``f = 9.2F;``    ``cout << ``"isnormal(9.2/0.0) is = "` `<< isnormal(f / 0.0) << endl;`` ` `    ``return` `0;``}`
Output:
```isnormal(7.0) is = 1
isnormal(0.0) is = 0
isnormal(9.2/0.0) is = 0
```

Example 2:- To show with double value

 `// c++ program to demonstrate``// example of isnormal() function.`` ` `#include `` ` `using` `namespace` `std;`` ` `int` `main()``{`` ` `    ``double` `f = 7.0;`` ` `    ``// check for non-zero value``    ``cout << ``"isnormal(7.0) is = "` `<< isnormal(f) << endl;`` ` `    ``// check for zero``    ``f = 0.0;``    ``cout << ``"isnormal(0.0) is = "` `<< isnormal(f) << endl;`` ` `    ``// check for infinite value``    ``f = 9.2;``    ``cout << ``"isnormal(9.2/0.0) is = "` `<< isnormal(f / 0.0) << endl;`` ` `    ``return` `0;``}`
Output:
```isnormal(7.0) is = 1
isnormal(0.0) is = 0
isnormal(9.2/0.0) is = 0
```

Example 3:- To show with long double value

 `// c++ program to demonstrate``// example of isnormal() function.`` ` `#include `` ` `using` `namespace` `std;`` ` `int` `main()``{`` ` `    ``long` `double` `f = 7.0;`` ` `    ``// check for non-zero value``    ``cout << ``"isnormal(7.0) is = "` `<< isnormal(f) << endl;`` ` `    ``// check for zero``    ``f = 0.0;``    ``cout << ``"isnormal(0.0) is = "` `<< isnormal(f) << endl;`` ` `    ``// check for infinite value``    ``f = 9.2;``    ``cout << ``"isnormal(9.2/0.0) is = "` `<< isnormal(f / 0.0) << endl;`` ` `    ``return` `0;``}`
Output:
```isnormal(7.0) is = 1
isnormal(0.0) is = 0
isnormal(9.2/0.0) is = 0
```
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