SoFunction
Updated on 2025-03-01

Solution description of floating point operation bug in js

This code was used by the project before. I found this code online before, but there will still be bugs in division and addition operations under specific conditions. I have made some optimizations on this.

Copy the codeThe code is as follows:

//Divide function is used to obtain accurate division results
//Note: There will be errors in the division result of javascript, which will be more obvious when dividing two floating point numbers. This function returns a more accurate 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 = ().split(".")[1].length } catch (e) { }
    try { t2 = ().split(".")[1].length } catch (e) { }
    with (Math) {
        r1 = Number(().replace(".", ""))
        r2 = Number(().replace(".", ""))
        return accMul((r1 / r2),pow(10, t2 - t1));
    }
}

Copy the codeThe code is as follows:

//Multiple function is used to obtain accurate multiplication results
//Note: There will be errors in the multiplication result of javascript, which will be more obvious when multiplying two floating point numbers. This function returns a more accurate multiplication result.
//Call: accMul(arg1,arg2)
//Return value: the exact result of arg1 multiplied by arg2
function accMul(arg1, arg2) {
    var m = 0, s1 = (), s2 = ();
    try { m += (".")[1].length } catch (e) { }
    try { m += (".")[1].length } catch (e) { }
    return Number((".", "")) * Number((".", "")) / (10, m)
}

Copy the codeThe code is as follows:

//Intermediate solution to addition operation
function accAdd(arg1, arg2) {  
    var r1, r2, m, c;
    try { r1 = ().split(".")[1].length } catch (e) { r1 = 0 }
    try { r2 = ().split(".")[1].length } catch (e) { r2 = 0 } 
    c = (r1 - r2);  
    m = (10, (r1, r2))  
    if (c > 0) {  
        var cm = (10, c);  
        if (r1 > r2) {  
            arg1 = Number(().replace(".", ""));  
            arg2 = Number(().replace(".", "")) * cm;  
        }  
        else {  
            arg1 = Number(().replace(".", "")) * cm;  
            arg2 = Number(().replace(".", ""));  
        }  
    }  
    else {  
        arg1 = Number(().replace(".", ""));  
        arg2 = Number(().replace(".", ""));  
    }  
    return accDiv((arg1 + arg2),m);
}