Accurate calculation of js floating point numbers-JS Tutorial-php.cn

Accurate calculation of js floating point numbers

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Release： 2017-10-16 10:07:43

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//Division function, used to obtain accurate division results
//Explanation: The division result of JavaScript will have errors, which will be more obvious when dividing two floating point numbers. This function returns a more accurate division result.
//Call: accp(arg1,arg2)
//Return value: the exact result of dividing arg1 by arg2

function accp(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);
    }
}

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//Increase the Number type A p method is more convenient to call.
Number.prototype.p = function (arg){
return accp(this, arg);
}
//Multiplication function, used to obtain accurate multiplication results
//Explanation : The multiplication result of JavaScript will have errors, which will be more obvious when two floating point numbers are multiplied. This function returns a more accurate multiplication result.
//Call: accMul(arg1,arg2)
//Return value: The exact result of multiplying arg1 by arg2

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);
}

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//Increase the Number type A mul method is more convenient to call.

Number.prototype.mul = function (arg){
    return accMul(arg, this);
};

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//Addition function, used to obtain accurate addition results
//Explanation: The addition result of JavaScript will have errors, which will be more obvious when adding two floating point numbers. This function returns a more accurate addition result.
//Call: accAdd(arg1,arg2)
//Return value: the exact result of arg1 plus arg2

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;
}

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//给Number类型增加一个add方法，调用起来更加方便。
Number.prototype.add = function (arg){
    return accAdd(arg,this);
}
//减法函数
function accSub(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));
     //last modify by deeka
     //动态控制精度长度
     n=(r1>=r2)?r1:r2;
     return ((arg2*m-arg1*m)/m).toFixed(n);
}
///给number类增加一个sub方法，调用起来更加方便
Number.prototype.sub = function (arg){
    return accSub(arg,this);
}

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