Question

Wanna know how come the error only appears in IE
Can it work by modifying?
3q.

Function
input: 192.2.09.001
output: 192.2.9.1

ERROR@IE
input: 192.2.09.001
output:  undefinedundefinedundefined.undefined.undefinedundefined.undefinedundefinedundefined

Code:
ip_normalize(ip)

function remove_0(input)
{

    var i;
    var output_string="";
    var tag=0;
    for (i=0; i< input.length ; i++)
    {
            if(i==input.length-1 || tag==1)
            {
                    output_string+= input[i];
            }
            else
            {
                    if(input[i]!='0')
                    {
                            output_string+= input[i];
                            tag=1;
                    }
            }
    }
    return output_string;
}

function ip_normalize(ip)
{
    var ip_s = ip.split('.');
    var ip_n = "";
    var ip1="",ip2="",ip3="",ip4="";
    if(ip_s.length!=4)
            return ip;
    ip1 = remove_0(ip_s[0]);
    ip2 = remove_0(ip_s[1]);
    ip3 = remove_0(ip_s[2]);
    ip4 = remove_0(ip_s[3]);

    ip_n = ip1 + '.' + ip2 + '.' + ip3 + '.' + ip4;

    return ip_n;
}

Answer 1

Can’t you simply use:

function ip_normalize(ip)
{
    var ip_s = ip.split('.', 4);
    if (ip_s.length != 4) return ip;
    return parseInt(ip_s[0], 10) + "." +
           parseInt(ip_s[1], 10) + "." + 
           parseInt(ip_s[2], 10) + "." + 
           parseInt(ip_s[3], 10);
}