JSFiddle - React, Tailwind, and code Playground

JavaScript

var map, errors, result;
errors = new Map();
errors.set(NaN, "That was not a number!");
errors.set(Infinity, "That was infinity!");
[
    1 + 2,
    1/0,
    1/"foo",
].forEach(function (result) {
    if (errors.has(result)) {
        console.log(errors.get(result));
    } else {
        console.log("The result was", result);
    }
});