JS浮点计算BUG屏蔽终极解决办法
//四舍五入
/*JS浮点计算BUG屏蔽终极解决办法*/

/*
第一部分
重写Number函数,增加3个函数，加、乘、除
*/

Number.prototype.add = function(arg) {

return accAdd(arg, this);

}
//接口
//相除
Number.prototype.div = function(arg) {

return accDiv(this, arg);

}

//乘法
//使用方法 5.mul(4)=20
Number.prototype.mul = function(arg) {

return accMul(arg, this);

}

//============================================

/*
第二部分
加、乘、除具体函数，
*/

//相除
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) { }

with (Math) {

r1 = Number(arg1.toString().replace(".", ""))

r2 = Number(arg2.toString().replace(".", ""))

return (r1 / r2) * pow(10, t2 - t1);

}

}

//相乘
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)

}


//相加
function accAdd(arg1, arg2) {

var r1, r2, m, c;

try { r1 = arg1.toString().split(".")[1].length } catch (e) { r1 = 0 }

try { r2 = arg2.toString().split(".")[1].length } catch (e) { r2 = 0 }

c = Math.abs(r1 - r2);
m = Math.pow(10, Math.max(r1, r2))
if (c > 0) {
var cm = Math.pow(10, c);
if (r1 > r2) {
arg1 = Number(arg1.toString().replace(".", ""));
arg2 = Number(arg2.toString().replace(".", "")) * cm;
}
else {
arg1 = Number(arg1.toString().replace(".", "")) * cm;
arg2 = Number(arg2.toString().replace(".", ""));
}
}
else {
arg1 = Number(arg1.toString().replace(".", ""));
arg2 = Number(arg2.toString().replace(".", ""));
}
return (arg1 + arg2) / m
}