Js floating point operation BUG solution
- 2020-03-30 01:12:48
- OfStack
I used it in a project where I found this code on the web, but under certain conditions there were still bugs in division and addition and I personally optimized it a little bit
//Division function, used to get accurate division results
//Note: javascript division results will have errors, in two floating point division will be more obvious. This function returns a more precise division result.
//Call: accDiv (arg1, arg2)
//Return value: the exact result of arg1 divided by arg2
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 accMul((r1 / r2),pow(10, t2 - t1));
}
}
//The multiplication function, which is used to get exact multiplication results
//Note: javascript multiplication results will have errors, in the two floating point number multiplication will be more obvious. This function returns a more precise multiplication result.
//Call: accMul (arg1, arg2)
//Return value: the exact result of arg1 times 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)
}
//Intermediate solution for addition
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 accDiv((arg1 + arg2),m);
}