Question

What is NaN? What is its type? How can you reliably test if a value is equal to NaN?

Answer 1

NaN stands for 'Not a Number' and is a special value in programming that represents an undefined or unrepresentable result of a mathematical operation. To reliably test if a value is equal to NaN, you can use the isNaN() function in JavaScript or the isNaN() function in Python.

Step-by-step explanation:

NaN stands for 'Not a Number' and is a special value in programming that represents an undefined or unrepresentable result of a mathematical operation.

NaN is of type 'number'. However, it is important to note that NaN is not equal to any other value, including itself. So, to reliably test if a value is equal to NaN, you can use the isNaN() function in JavaScript or the isNan() function in Python. These functions return true if the value is NaN and false otherwise.