Skip to content

Latest commit

 

History

History
127 lines (95 loc) · 4.35 KB

README_zh-CN.md

File metadata and controls

127 lines (95 loc) · 4.35 KB

JSBI-Calculator

License Coverage GitHub Workflow Status GitHub release NPM

JSBI-Calculator是一个IE11兼容的计算器JS库组件,用于实现高精度(至多18位小数)大数值四则运算,基于由谷歌Chrome实验室出品的JSBI封装的BigDecimal。

该项目反哺GoogleChromeLabs/jsbi作出了不凡贡献。

安装

> npm install jsbi-calculator

示例

Showcase

用法

ES6模块:

import JBC from "jsbi-calculator";

const { calculator } = JBC;

const expressionOne = "((10 * (24 / ((9 + 3) * (-2)))) + 17) + 5";
const resultOne = calculator(expressionOne);
console.log(resultOne);
// -> '12'

const max = String(Number.MAX_SAFE_INTEGER);
console.log(max);
// -> '9007199254740991'
const expressionTwo = `${max} + 2`;
const resultTwo = calculator(expressionTwo);
console.log(resultTwo);
// -> '9007199254740993'

Node CommonJS模块:

const JBC = require("jsbi-calculator");

const { calculator } = JBC;

const expressionOne = "((10 * (24 / ((9 + 3) * (-2)))) + 17) + 5";
const resultOne = calculator(expressionOne);
console.log(resultOne);
// -> '12'

const max = String(Number.MAX_SAFE_INTEGER);
console.log(max);
// -> '9007199254740991'
const expressionTwo = `${max} + 2`;
const resultTwo = calculator(expressionTwo);
console.log(resultTwo);
// -> '9007199254740993'

浏览器:

<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Jsbi-calculator Test</title>
    <script src="https://cdn.jsdelivr.net/npm/jsbi-calculator/dist/jsbi-calculator-umd.js"></script>
  </head>
  <body></body>
  <script type="text/javascript">
    const expressionOne = "((10 * (24 / ((9 + 3) * (-2)))) + 17) + 5";
    const resultOne = JBC.calculator(expressionOne);
    console.log(resultOne);
    // -> '12'

    const userAgent = navigator.userAgent;
    const isIE11 =
      userAgent.indexOf("Trident") > -1 && userAgent.indexOf("rv:11.0") > -1;
    let max;
    // MAX_SAFE_INTEGER not available in IE11
    max = isIE11 ? "9007199254740991" : String(Number.MAX_SAFE_INTEGER);

    console.log(max);
    // -> '9007199254740991'
    const expressionTwo = max + " + 2";
    const resultTwo = JBC.calculator(expressionTwo);
    console.log(resultTwo);
    // -> '9007199254740993'
  </script>
</html>

注意

下面表格中的运算操作是有涉及到的。请注意,负数需要以-开头且需要用括号括起来,例如(-11),正数不能以+号开头。

运算操作 运算符号
加法 +
减法 -
乘法 *
除法 /
平方根 JBC.BigDecimal.sqrt(num).toString()

致谢

项目开发得到了下列资源的灵感启发。

GoogleChromeLabs/jsbi

trincot's answer to BigDecimal in JavaScript

LeetCode150 - Evaluate Reverse Polish Notation

Parsing math expressions with JavaScript - FreeCodeCamp