Sum of two possible undefined numbers in typescript-CodePudding

I'm trying to write a function that returns the sum of two attributes that can also be undefined. This is what I wrote:

function sumPossibleUndefinedValues(availability: T): number | undefined {
    const firstNumber = availability.first; //can be undefined
    const secondNumber = availability.second; //can be undefined

    return firstNumber !== undefined
        ? firstNumber   (secondNumber || 0)
        : secondNumber !== undefined
        ? secondNumber
        : undefined;
}

Now, I'm wondering if there's a better way to write this return statement.

CodePudding user response：

You can try that:

return firstNumber   secondNumber || firstNumber || secondNumber;

If the left side is undefined or NaN it tries the next one until secondNumber and in that case the value of secondNumber is returned.

CodePudding user response：

You can try this

return (availability?.first || 0) (availability?.second || 0)