Processing of decimal type data in JS (high precision calculation)

introduce

Decimal is a data type of databases such as SQL Server and MySql . It does not belong to the floating-point number type, and the number of digits in the integer part and the decimal part can be delineated when defining . Using the exact decimal type can not only ensure more accurate data calculation, but also save storage space

import file

Reference for npm directives

/**  Node.js  */

$ npm install --save decimal.js
var Decimal = require('decimal.js');

/** ES6 模块方式 */

import { Decimal } from 'decimal.js';//刚刚加入时IDEA可能还没反应所以显示灰色，过会就好了

use

//加法运算
var a = 0.13;
var b = 0.25;
console.log('加法运算 a + b =', a + b);
console.log('使用Decimaljs a + b =', new Decimal(a).add(new Decimal(b)).toNumber());

//减法
var a = 1.0;
var b = 0.99
console.log('直接减法运算 a - b =', a - b);
console.log('使用Decimaljs a - b =', new Decimal(a).sub(new Decimal(b)).toNumber().toFixed(2);//保留两位数据

//乘法
var a = 1.01;
var b = 1.02;
console.log('直接乘法运算 a * b =', a * b);
console.log('使用Decimaljs a * b =', new Decimal(a).mul(new Decimal(b)).toNumber());

//除法
var a = 0.033;
var b = 10;
console.log('直接除法运算 a / b =', a / b);
console.log('使用Decimaljs a / b =', new Decimal(a).div(new Decimal(b)).toNumber());