math-precision

.round, .ceil, .floor with precision parameter. E.g. .round(1.234, 2) → 1.23

This node.js package gives you a cleaner way to round numbers using precision . It's simple, lightweight and it relies entirely on JS Math functions. It has no dependencies and it works on any node.js version. It's a pity not to use it! :)

All world wide web documentation about decimal rounding in JavaScript, including Mozilla Docs lead us to this solution:

E.g. To round 1.2347 with precision 3 you should call:
Math.round(1.2347 * 1000) / 1000 // = 1.235

which is what this package actually does behind the scenes if you call: .round(1.2347, 3) (check the source code)

The options are: to write an ugly code, to create a function and copy/paste it everywhere, to export the function from your own utility library or to require this package ... you choose! :)

Anyway there are several npm packageswhich does the same thing but I find this the straightforward way to do it.

It also de deals with negative precision .round(1234, -2) = 1200

See other examples or run the tests

Install

$ npm install math-precision

Examples

.round

var round = require('math-precision').round
 
console.log(round(1.2347, 2))        // 1.23
console.log(round(1.235, 2))         // 1.24
console.log(round(1.2, 2))           // 1.2
console.log(round(1.24569, 3))       // 1.246
console.log(round(1234, -2))         // 1200
console.log(round(12785.9, -3))      // 13000
console.log(round(1.2347))           // 1
console.log(round(1.2347, NaN))      // 1
console.log(round(undefined, 2))     // NaN
console.log(round(NaN, 2))           // NaN

.ceil

var ceil = require('math-precision').ceil
 
console.log(ceil(1.2347, 2))         // 1.24
console.log(ceil(1.2, 2))            // 1.2
console.log(ceil(1.2341, 3))         // 1.235
console.log(ceil(1234, -2))          // 1300
console.log(ceil(123436.87, -3))     // 124000
console.log(ceil(1.2347))            // 2
console.log(ceil(1.2347, NaN))       // 2
console.log(ceil(undefined, 2))      // NaN
console.log(ceil(NaN, 2))            // NaN

.floor

var floor = require('math-precision').floor
 
console.log(floor(1.2361, 2))        // 1.23
console.log(floor(1.2367, 3))        // 1.236
console.log(floor(1.8, 2))           // 1.8
console.log(floor(1876, -2))         // 1800
console.log(floor(187697.78, -3))    // 187000
console.log(floor(1.2361))           // 1
console.log(floor(1.2361, NaN))      // 1
console.log(floor(undefined, 2))     // NaN
console.log(floor(NaN, 2))           // NaN

using math object

var math = require('math-precision')
 
console.log(math.round(1.2358, 2))   // 1.24
console.log(math.ceil(1.2358, 2))    // 1.24
console.log(math.floor(1.2358, 2))   // 1.23

Test

Simply clone the repo, npm install, and run npm test

License

MIT