js-money

!NPM versionnpm-imagenpm-url !Downloadsdownloads-imagenpm-url JS Money is a JavaScript implementation of Martin Fowlers Money pattern.

Install

The package is available through npm and bower.

$ npm install js-money

$ bower install js-money

Usage

First we need to import the library. ```javascript var Money = require('js-money'); ```

Creating a new instance

There are multiple options of what to pass into the constructor to create a new Money instance:

• amount as number, currency as string

• amount as number, currency as object

• object with amount and currency fields (only with fromInteger and fromDecimal methods)

Amounts can be supplied either as integers or decimal numbers. Instances of Money are immutable and each arithmetic operation will return a new instance of the object. When using decimals the library will allow only decimals with the precision allowed by the currencies smallest unit. ```javascript var fiveEur = new Money(500, Money.EUR); var tenDollars = Money.fromInteger({ amount: 1000, currency: Money.USD }); var someDollars = Money.fromDecimal(15.25, 'USD'); // the following will fail and throw an Error since USD allows for 2 decimals var moreDollars = Money.fromDecimal(15.3456, Money.USD); // but with rounder function provider the following will work var someMoreDollars = Money.fromDecimal(15.12345, 'USD', Math.ceil); ``` The currency object hold the following properties ```javascript

{

"symbol": "$",

"name": "US Dollar",

"symbol_native": "$",

"decimal_digits": 2,

"rounding": 0,

"code": "USD",

"name_plural": "US dollars"

}

```

Basic arithmetics

Arithmetic operations involving multiple objects are only possible on instances with the same currency and will throw an Error otherwise. ```javascript var fiveEur = new Money(500, Money.EUR); // 5 EUR // add fiveEur.add(new Money(250, Money.EUR)); // 7.50 EUR // subtract fiveEur.subtract(new Money(470, Money.EUR)); // 0.30 EUR // multiply fiveEur.multiply(1.2345); // 6.17 EUR fiveEur.multiply(1.2345, Math.ceil); // 6.18 EUR // divide fiveEur.divide(2.3456); // 2.13 EUR fiveEur.divide(2.3456, Math.ceil); // 2.14 EUR ```

Allocating funds

Will divide the funds based on the ratio without loosing any pennies. ```javascript var tenEur = new Money(1000, Money.EUR); // divide 10 EUR into 3 parts var shares = tenEur.allocate(1,1,1); // returns an array of Money instances worth 334,333,333 // split 5 EUR 70/30 var fiveEur = new Money(500, Money.EUR); var shares = fiveEur.allocate(70,30); // returns an array of money 350,150 ```

Comparison and equality

Two objects are equal when they are of the same amount and currency. Trying to compare 2 objects with different currencies will throw an Error. ```javascript var fiveEur = new Money(500, Money.EUR); var anotherFiveEur = new Money(500, Money.EUR); var sevenEur = new Money(700, Money.EUR); var fiveDollars = new Money(500, Money.USD); fiveEur.equals(fiveDollars); // return false fiveEur.equals(anotherFiveEur); // return true fiveEur.compare(sevenEur); // return -1 sevenEur.compare(fiveEur); // return 1 fiveEur.compare(anotherFiveEur); // return 0 fiveEur.compare(fileDollars); // throw Error fiveEur.greaterThan(sevenEur); // return false fiveEur.greaterThanOrEqual(sevenEur); // return false fiveEur.lessThan(sevenEur); // return true fiveEur.lessThanOrEqual(fiveEur); // return true ```

Tests

$ npm install

$ npm test

License

The MIT License Copyright (c) 2014 David Kalosi http://davidkalosi.com/