矫正js浮点数运算精度的库

Question

有没有这样的库？
网上找了一些代码，感觉还是不靠谱，而且还用到了with语句。
math.io上的库太多，找了半天，也没有找到
求个靠谱的运算库，主要用在前端不是在node。所以尽量轻量最好。
谢谢

Answer 1

Math.add = function(v1, v2)
 {
    ///<summary>精确计算加法。语法：Math.add(v1, v2)</summary>
    ///<param name="v1" type="number">操作数。</param>
   ///<param name="v2" type="number">操作数。</param>
   ///<returns type="number">计算结果。</returns>
   var r1, r2, m;
    try
        { 
            r1 = v1.toString().split(".")[1].length;
        }
    catch (e)
        {
          r1 = 0;
        }
    try
    {
      r2 = v2.toString().split(".")[1].length;
    }
    catch (e)
    {
      r2 = 0;
    }
    m = Math.pow(10, Math.max(r1, r2));

    return (v1 * m + v2 * m) / m;
  }


  Number.prototype.add = function(v)
  {
  ///<summary>精确计算加法。语法：number1.add(v)</summary>
  ///<param name="v" type="number">操作数。</param>
  ///<returns type="number">计算结果。</returns>
    return Math.add(v, this);
  }


  Math.sub = function(v1, v2)
  {
  ///<summary>精确计算减法。语法：Math.sub(v1, v2)</summary>
  ///<param name="v1" type="number">操作数。</param>
  ///<param name="v2" type="number">操作数。</param>
  ///<returns type="number">计算结果。</returns>
    return Math.add(v1, -v2);
  }


  Number.prototype.sub = function(v)
  {
  ///<summary>精确计算减法。语法：number1.sub(v)</summary>
  ///<param name="v" type="number">操作数。</param>
  ///<returns type="number">计算结果。</returns>
    return Math.sub(this, v);
  }


  Math.mul = function(v1, v2)
  {
  ///<summary>精确计算乘法。语法：Math.mul(v1, v2)</summary>
  ///<param name="v1" type="number">操作数。</param>
  ///<param name="v2" type="number">操作数。</param>
  ///<returns type="number">计算结果。</returns>
    var m = 0;
    var s1 = v1.toString();
    var s2 = v2.toString();
    try
    {
      m += s1.split(".")[1].length;
    }
    catch (e)
    {
    }
    try
    {
      m += s2.split(".")[1].length;
    }
    catch (e)
    {
    }

    return Number(s1.replace(".", "")) * Number(s2.replace(".", "")) / Math.pow(10, m);
  }


  Number.prototype.mul = function(v)
  {
  ///<summary>精确计算乘法。语法：number1.mul(v)</summary>
  ///<param name="v" type="number">操作数。</param>
  ///<returns type="number">计算结果。</returns>
    return Math.mul(v, this);
  }


  Math.div = function(v1, v2)
  {
  ///<summary>精确计算除法。语法：Math.div(v1, v2)</summary>
  ///<param name="v1" type="number">操作数。</param>
  ///<param name="v2" type="number">操作数。</param>
  ///<returns type="number">计算结果。</returns>
    var t1 = 0;
    var t2 = 0;
    var r1, r2;
    try
    {
      t1 = v1.toString().split(".")[1].length;
    }
    catch (e)
    {
    }
    try
    {
      t2 = v2.toString().split(".")[1].length;
    }
    catch (e)
    {
    }

    with (Math)
    {
      r1 = Number(v1.toString().replace(".", ""));
      r2 = Number(v2.toString().replace(".", ""));
      return (r1 / r2) * pow(10, t2 - t1);
    }
  }


  Number.prototype.div = function(v)
  {
  ///<summary>精确计算除法。语法：number1.div(v)</summary>
  ///<param name="v" type="number">操作数。</param>
  ///<returns type="number">计算结果。</returns>
    return Math.div(this, v);
  }

Answer 2

一般的业务代码用toFixed搭配parseFloat就可以实现“精确计算”。

  2.3/100000
  //=> 0.000022999999999999997
  parseFloat((2.3/100000).toFixed(16))
  //=> 0.000023

  0.0000211 * 100
  //=> 0.0021100000000000003
  parseFloat((0.0000211 * 100).toFixed(16))
  //=> 0.00211

Answer 3

numbers.js或者math.js都可以，至少这两个做浮点运算肯定都没问题

Answer 4

crunch.js

Answer 5

阿里巴巴浮点数计算库：https://github.com/nefe/numbe...