How do I check if a variable is an imaginary number inside JavaScript?

Question

I am making a calculator, and I don't want NaN to show up for results of imaginary/complex numbers, and instead just an error message. How would I check this inside of JavaScript?

I looked around on the web but couldn't find a definitive answer.

Answer 1

You can use isNaN().

let x;

const rand = Math.round(Math.random());

if (rand) x = 5 + 1;
else x = 5 + "a";

if (isNaN(x)) console.log("error");
else console.log(x);