JS: Number.isNaN
Number.isNaN(number)-
If number is NaN, return
true, elsefalse.console.assert(Number.isNaN(NaN)); // s------------------------------ console.assert(Number.isNaN("NaN") === false); console.assert(Number.isNaN("3") === false); console.assert(Number.isNaN(3) === false); console.assert(Number.isNaN(Infinity) === false); console.log(Number.isNaN("abc")); // false