A rounding library for JavaScript that behaves predictably (unlike Math.round, Math.floor, Math.ceil).
npm install reliable-roundA reliable rounding library for JavaScript/TypeScript that actually behaves predictably (unlike Math.round).
``sh`
npm install reliable-round --save
`javascript
import { round } from "reliable-round";
console.log(round(1.005)); // Rounds to a whole integer, returning 1
console.log(round(1.005, 2)); // Rounds to 2 decimal places returning 1.01
`
Because JavaScript floating point math often results in quirky and unpredictable results.
The classic JS WTF example is:
`javascript
console.log(0.1 + 0.2);
// Evaluates to 0.30000000000000004
`
Maybe not what you expected right?
As for rounding, lets say you need to round to 2 decimal places then you can create your own function like this:
`javascript
function roundToTwoDecimalPlaces(value) {
return Math.round(value * 100) / 100;
}
console.log(roundToTwoDecimalPlaces(1.006));
// Returns 1.01 - Correct!
`
At first glace, the output of the above function looks correct. But unfortunately its only correct some of the time!
`javascript
console.log(roundToTwoDecimalPlaces(1.005));
// Returns 1 - Wrong!
// The correct answer is 1.01
`
If you deal with rounding many floats in JS you will inevitably encounter many quirky inconsistencies like this.
reliable-round to the rescue!
`javascript
import { round } from "reliable-round";
console.log(round(1.005, 2));
// Correctly returns 1.01
`
While you will get predictable, reliable results using reliable-round be aware that it is at the expense of performance. Traditional methods of rounding that use the Math` class are much faster but at the expense of accuracy. You need to decide what's more important for your use-case.
Got an issue or a feature request? Log it.
Pull-requests are also welcome. 😸