swap.js

function swap(n) {
    var arr = n.toString().split(''); // convert number to string then split into array

    if (arr.length > 2) {
        var swap_list = []; //  arrary to push newly swapped numbers

        for (var i = 0; i < arr.length; i++) {
            for (var j = 0; j < arr.length; j++) {
                if (i != j) {
                    new_arr = arr.slice(0); // copy old array 
                    
                    // Swap locations
                    var x = new_arr[i]; // save the old value for location i to a var
                    new_arr[i] = new_arr[j]; // now change location i value to the value in location j
                    new_arr[j] = x; //location j can now take the value in x, which was i's former value
                    
                    // Forget items that begin with 0 
                    if (new_arr[0] != '0') { 
                        item = parseInt(new_arr.join('')); // convert result array back to integer
                        swap_list.push(item); //push item into the swap combo list
                    }
                }
            }
        }
        // with temp_list we find the highest and lowest numbers 
        var highest = "Highest swap is " + Math.max.apply(null, swap_list);
        var lowest = "Lowest swap is " + Math.min.apply(null, swap_list);
        console.log(highest);
        console.log(lowest);

    }
}