js加减乘除函数

经常用到算数的时候，可以直接用；
// 除法函数
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);
}
}
// 乘法函数
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)
}
// 加法函数
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
return accDiv((accMul(arg1, m) + accMul(arg2, m)), m)
}
// 减法函数
function accSubtr(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)
}