high-precision-four-fundamental-rules

a npm packge of high-precision-four-fundamental-rules, which can make up for the defect of accuracy of native JS.
（高精度的基本四则运算npm包，用来弥补原生JS计算精度缺失的缺陷）

Install

$ npm install high-precision-four-fundamental-rules --save

Usage

// type 1
import precisionArithmetic from 'high-precision-four-fundamental-rules';
precisionArithmetic.add(1, 2, 4); // '3.0000'
precisionArithmetic.subtract(1, 2, 3); // '-1.000';
precisionArithmetic.multiply(1, 2, 2); // '2.00';
precisionArithmetic.divide(1, 3, 7); // '0.3333333';
// type 2
import {add, subtract, multiply, divide} from 'high-precision-four-fundamental-rules';
add(1, 2, 4); // '3.0000'
subtract(1, 2, 3); // '-1.000';
multiply(1, 2, 2); // '2.00';
divide(1, 3, 7); // '0.3333333';

API

add（加法）

precisionArithmetic.add(num1, num2, fixedLength);

num, num2

Require: true
Type: number or string

fixedLength

Require: false
Type: number

subtract（减法）

precisionArithmetic.subtract(num1, num2, fixedLength);

num, num2

Require: true
Type: number or string

fixedLength

Require: false
Type: number

multiply（乘法）

precisionArithmetic.multiply(num1, num2, fixedLength);

num, num2

Require: true
Type: number or string

fixedLength

Require: false
Type: number

divide（除法）

precisionArithmetic.divide(num1, num2, fixedLength);

num, num2

Require: true
Type: number or string

fixedLength

Require: false
Type: number

Warning

In consideration of toFixed function in JavaScript not applicable to most high precision scenes like invoice amount or banking business, I rewrite it by rounding way. You can see the source code in index.js.

（考虑到原生JS中toFixed方法并不适用于银行或发票业务等高精度场景，作者用四舍五入算法重写了改方法，你可以在index.js看到源码。