Всем привет! Почему 'y' undefined? function multi(x,y){ var res =

Question

Всем привет! Почему 'y' undefined? function multi(x,y){ var res =

"0";
var zero = "0000";
var flag = false;
var one = "1111";
var str1 = "0";
var str2 = "1";
console.log(typeof(x));
console.log(typeof(y));
if (x[0]==y[0]){
flag = true;
}
if (y[0] == 1){
y[0] = 0;
}
if (y[0] == 0){
y[0] = 1;
}
if (y.length > zero.length){
for(var i=0;i <= y.length - zero.
zero = str1.concat(zero);
}
}
if (y.length > one.length){
for(var i=0;i <= y.length - one
one = str2.concat(one);
}
}

while(y!=zero){
res = addition(a,res);
y = addition(y,one);
}
if (flag == true)
{
res[0] = 0;
}
else
{
res[0] = 1;
}
return res;
}