Examples of how to format floating point numbers in JavaScript

format_floats.js

let output = 123.456789;

let precision = 2;

let mod = Math.pow(10, precision);
let a = Math.round(output * mod) / mod;
let b = output.toFixed(2);

console.log(a);
console.log(b);

/*
main differences is that toFixed, will always return the precision value, 
padding with zeros if necessary, where as Math.round will not pad.

Also, Math.round returns a number, while toFixed returns a string.
*/

output = 123;
a = Math.round(output * mod) / mod;
b = output.toFixed(2);

console.log(a, typeof a); //number
console.log(b, typeof b); //string