js 加减乘除失精

js 计算失精是因为js 先将10十进制代码转化为2进制，再计算导致

具体解决方案：

1. 加

function accAdd(arg1,arg2){ 
     var r1,r2,m; 
     try{r1=arg1.toString().split(".")[1].length}catch(e){r1=0} 
     try{r2=arg2.toString().split(".")[1].length}catch(e){r2=0} 
     m=Math.pow(10,Math.max(r1,r2)) 
     return (arg1*m+arg2*m)/m 
 } 

2. 减

function Subtr(arg1,arg2){
     var r1,r2,m,n;
     try{r1=arg1.toString().split(".")[1].length}catch(e){r1=0}
     try{r2=arg2.toString().split(".")[1].length}catch(e){r2=0}
     m=Math.pow(10,Math.max(r1,r2));
     n=(r1>=r2)?r1:r2;
     return ((arg1*m-arg2*m)/m).toFixed(n);
 }

更新：

个别情况， 加减依旧有问题， 更新如下：

//加
function accAdd(arg1, arg2) {
    var r1,
        r2,
        m,
        num1,
        num2;
    try {
        r1 = arg1.toString().split(".")[1].length;
    } catch (e) {
        r1 = 0
    }
    try {
        r2 = arg2.toString().split(".")[1].length;
    } catch (e) {
        r2 = 0
    }
    m = Math.pow(10, Math.max(r1, r2));
    num1 = r1 == 0? parseInt(arg1 * m): (parseInt(`${arg1.toString().replace('.', '')}`)*m/(Math.pow(10, r1)));
    num2 = r2 == 0? parseInt(arg2 * m): (parseInt(`${arg2.toString().replace('.', '')}`)*m/(Math.pow(10, r2)));
    return (num1 + num2) / m;
}

//减

function Subtr(arg1, arg2) {
    var r1,
        r2,
        m,
        n,
        num1,
        num2;
    try {
        r1 = arg1.toString().split(".")[1].length
    } catch (e) {
        r1 = 0
    }
    try {
        r2 = arg2.toString().split(".")[1].length
    } catch (e) {
        r2 = 0
    }
    m = Math.pow(10, Math.max(r1, r2));
    n = (r1 >= r2) ? r1 : r2;
    num1 = r1 == 0? parseInt(arg1 * m): (parseInt(`${arg1.toString().replace('.', '')}`)*m/(Math.pow(10, r1)));
    num2 = r2 == 0? parseInt(arg2 * m): (parseInt(`${arg2.toString().replace('.', '')}`)*m/(Math.pow(10, r2)));
    return ((num1 - num2) / m).toFixed(n);
}

　　

3.乘

function accMul(arg1,arg2) { 
   var m=0,s1=arg1.toString(),s2=arg2.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) 
} 

4.除

function accDiv(arg1,arg2){ 
  var t1 = 0, t2 = 0, r1, r2;
    try {
        t1 = arg1.toString().split(".")[1].length
    } catch (e) {}
    try {
        t2 = arg2.toString().split(".")[1].length
    } catch (e) {}
    r1 = Number(arg1.toString().replace(".", ""))
    r2 = Number(arg2.toString().replace(".", ""))
    return getMultiFormat((r1 / r2), Math.pow(10, t2 - t1));
}