JS 浮点加减乘除运算

function FloatAdd(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   
}   

function FloatSub(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));   
    //动态控制精度长度   
    n=(r1>=r2)?r1:r2;   
    return ((arg1*m-arg2*m)/m).toFixed(n);   
}   

function FloatMul(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)   
}   

function FloatDiv(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){}   
    with(Math){   
        r1=Number(arg1.toString().replace(".",""))   
        r2=Number(arg2.toString().replace(".",""))   
        return (r1/r2)*pow(10,t2-t1);   
    }   
}