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In TypeScript, how can we check if some value is NaN?
The following does not work:
someObject.someValue == NaN someObject.someValue === NaN 
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To check if a value is NaN , call the Number. isNaN() method, passing it the value as a parameter. The Number. isNaN method returns true if the passed in value is NaN and has a type of number , otherwise it returns false .
NaN in Typescript stands for Not a Number. It is the result of numerical operations, where result is not a number . It is the property of the global object. You can refer it either as NaN or Number.
isNaN() Method: To determine whether a number is NaN, we can use the isNaN() function. It is a boolean function that returns true if a number is NaN otherwise returns false.
A semi-reliable way to test whether a number is equal to NaN is with the built-in function isNaN(), but even using isNaN() is an imperfect solution. A better solution would either be to use value !== value, which would only produce true if the value is equal to NaN.
Same as JavaScript, isNaN.
if (isNaN(someObject.someValue)) ... Or the more modern Number.isNaN
if (Number.isNaN(someObject.someValue)) ... If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
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