Negative Infinity in C++

In C++, we can use the std::numeric_limits<T>::infinity() function from the <limits> library that returns the value of positive infinity and then we can multiply it by “-1” to make it negative. When a negative infinity is obtained it can then be used for various purposes like Initializing variables to negative infinity, comparing values, and using it as a lower bound in algorithms that require range checking, etc.

Syntax to Define Negative Infinity

dataType negInfinity = -std::numeric_limits<dataType>::infinity();

Here, dataType is a non-integral data (float or double).

In C++, the infinity is written as inf. We get infinity as a result when a positive number is divided by a null value or when a value is much greater and cannot be stored in 64-bit. In C++, positive infinity is defined in many libraries but the negative infinity is not defined. In this article, we will learn how to define and use the negative infinity in C++.