Hi! Im making the Symmetric difference challenge. I created a code that resolves the symmetric difference for two arrays, but i don’t know how to use reduce to extend it two several variables.

```
var args = Array.prototype.slice.call(arguments);
function deleteAll(arr,num) {
arr=arr.filter(function(value){
return (value!==num);
});
return arr;
}
function diff(arr1,arr2){
for(var i=0;i<arr1.length;i++){
for(var j=0;j<arr2.length;j++){
if(arr1[i]===arr2[j]) {
arr1=deleteAll(arr1,arr1[i]);
i-=1;
}
}
}
return arr1;
}
function sym(arr1,arr2) {
return (diff(arr1,arr2).concat(diff(arr2,arr1)));
}
sym([1, 2, 3], [5, 2, 1, 4]);
```