nanf flash校验_C ++中带有示例的nanf（）函数

nanf flash校验

C ++ Nanf()函数 (C++ nanf() function)

nanf() function is a library function of cmath header, it is used to get the NaN value of type float. It accepts an argument (which is an implementation-specific C String – to get NaN value we have to pass an empty string), it returns NaN value of type float.

nanf()函数是cmath标头的库函数，用于获取float类型的NaN值。它接受一个参数(它是特定于实现的C字符串-要获取NaN值，我们必须传递一个空字符串)，它返回float类型的NaN值。

Not-A-Number (NaN) values are used to check whether the value is an unidentified/non-representable or not? For example, the square root of a negative number is unidentified.

非数字(NaN)值用于检查该值是否为未识别/不可代表？例如，负数的平方根不确定。

Syntax of nanf() function:

nanf()函数的语法：

C++11:

C ++ 11：

    float nanf (const char* tagp);

Parameter(s):

参数：

tagp – represents an implementation-specific C-String.
tagp –表示特定于实现的C-String。

Return value:

返回值：

The return type of this method is float, it returns NaN value.

此方法的返回类型为float ，它返回NaN值。

Example:

例：

    Function call:
nanf("");    
Output:
nan

C ++代码演示nanf()函数的示例 (C++ code to demonstrate the example of nanf() function)

// C++ code to demonstrate the example of
// nanf() function
#include <iostream>
#include <cmath>
using namespace std;
// main() section
int main()
{
float nanValue;
//generating generic NaN value
//by passing an empty string
nanValue = nanf("");
//printing the value
cout << "nanValue: " << nanValue << endl;
return 0;
}

Output

输出量