There are two ways to correctly type checks number:
console.log(typeof 99.66); // number console.log(Object.prototype.toString.call(99) === '[object Number]'); // true
When using Number.prototype methods, some of them return String as result:
console.log((99.12345678).toPrecision(5)); // 99.123
We can see this string:
console.log(typeof (99.12345678).toPrecision(5)); // string
If we want to conver this string type of number:
console.log(parseFloat((99.12345678).toPrecision(5))); // 99.123
Last in Chrome dev tool, you can see that, Number is shown in Blue color, and string is shown in Black color:
console.log(parseFloat((99.12345678).toPrecision(5)));
console.log((99.12345678).toPrecision(5));
