C++ NaN: Explanation and Usage

In C++, “nan” stands for “Not a Number” which represents a special non-numeric value. NaN typically occurs in mathematical operations to indicate an invalid or undefined result. In C++, NaN is usually represented as std::numeric_limits::quiet_NaN(). NaN can be used to represent invalid floating-point operation results, such as division by 0 or taking the square root of a negative number. NaN is commonly used as a flag for error handling or special cases.