IsNaN is a JavaScript function that is used to decide if a value is NaN (Not-a-Number) or not. NaN (Not-a-Number) is a value in JavaScript that represents an invalid or unrepresentable number, for example the result of dividing zero by zero or the square root of a negative number. The purpose of isNaN is to see if a value is NaN (Not-a-Number) or not. This function takes one argument, which is the value that gets tested and if the argument is NaN then the function comes back as true. But if the argument is not NaN (a number or can be converted to a number), the function comes back as false. Overall IsNaN is great for checking if a value is a NaN or not when using JavaScript.
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Hi Ryan, thanks for your response! When would you have a reason to use this? I think what I don’t understand is that usually we are aware of when something is not a number, because the conditions you mentioned of dividing by zero or an imaginary number are easy to see. Would this come up in lines of code with a lot of calculations that wouldn’t be easy for the coder to follow? I would be curious to hear a real-world example, if you have any.