Just for interest. We have that NaN is spreading along side calculation.

1   NaN => NaN

Is there any operator which will stop this spreading. I mean something like:

<operator> NaN => number

or

NaN <operator> <operand> => number

or

<operand> <operator> NaN => number

NaN => number

CodePudding user response：

Actually in Ecmascript definition of (**) operator for numbers. Has a special case when second operand is 0 or -0.

https://tc39.es/ecma262/multipage/ecmascript-data-types-and-values.html#sec-numeric-types-number-exponentiate

So actually:

console.log(NaN ** 0) // will log 1

CodePudding user response：

The Javascript has a built-in method that detect a NaN, but you will need check this "Possible number" for each operand.

let possibleNumber = "4f";

console.log(isNaN(Number(possibleNumber)));

possibleNumber = "44";

console.log(isNaN(Number(possibleNumber)));

Output:

true
false

You can do some function to check and return some number that you want

function checkIfIsNaN(number,numIfTrue,numIfFalse){
    if(isNaN(Number(number))){ return numIfTrue} else{return numIfFalse};
}

console.log(checkIfIsNaN("44",4,10));