Implement a simple iterator using javascript (node.js)

The code is extremely simple, so just let the code tell you everything!

One point need to be pointed out I made use of node.js to write the following code:

/* implement a simple iterator without OOP */function iterator(values) {var n = arguments.length;var i = 0;var vals = arguments;     // must keep a reference to the "arguments" objectvar returnObj = {hasNext: function() {return i < n;    // because closure keep the reference to the variable, i will get changed as next() get called.},next: function() {if (i >= n) {throw new Error("end of iteration!");}return vals[i++];}};if (isArray(values)) {n = values.length;vals = arguments[0];// support for remove() methodreturnObj.remove = function() {if (i === 0) {throw new Error("must call next method first!");}vals.splice(i-1, 1);};}return returnObj;}/* to test if the given object is an array */function isArray(arr) {return arr.constructor.toString().indexOf("Array") > -1;}/* the following is the test code */console.log("variable-arity version");var iter = iterator(1, 2, 3, 4, 5, 6, 7, 8, 9, 0);while (iter.hasNext()) {console.log(iter.next());}console.log("array version");iter = iterator([1, 2, 3, 4, 5, 6, 7, 8, 9, 0]);while (iter.hasNext()) {console.log(iter.next());}console.log("array version, test remove method");var arr = [1, 2, 3, 4, 5, 6, 7, 8, 9, 0];console.log("before remove", arr);iter = iterator(arr);// iter.remove();  // "must call next method first" errorwhile (iter.hasNext()) {var item = iter.next();if (item % 2 === 0) {iter.remove();}}console.log("after remove", arr);// console.log(iter.next());   // "end of iteration" error

As you can see, it is not that trival. I am gonna show you another problem as a bonus (c/c++ version):

Requirement: extract all the numbers at the odd position from a sequence of numbers, and then sort them in an ascending order. After that, sort the left numbers in a descending order, and finally merge these two sorted sequences.

e.g., 1 2 7 4 8 6

odd: 1 7 8

even: 2 4 6

after sort

odd: 1 7 8

even: 6 4 2

after merge

1 6 7 4 8 2

#include <iostream>#include <vector>#include <string>#include <algorithm>using namespace std;bool greater(int a, int b){    return a > b;}bool less(int a, int b){    return a < b;}vector<int> splitStr(string str,string pattern){    int pos;    vector<int> result;    str += pattern;    int size=str.size();    for(int i=0; i<size; i++)    {        pos=str.find(pattern,i);        if(pos<size)        {            string s=str.substr(i,pos-i);            result.push_back(atoi(s.c_str()));            i=pos+pattern.size()-1;        }    }    return result;}vector<int> sortVec(vector<int> numVec){    vector<int> oddVec;    vector<int> evenVec;    vector<int> result;    for(unsigned int i = 0; i < numVec.size(); i++)    {        if(!(i & 0x1))        {            oddVec.push_back(numVec[i]);        }        else        {            evenVec.push_back(numVec[i]);        }    }    sort(oddVec.begin(), oddVec.end(), less);    sort(evenVec.begin(), evenVec.end(), greater);    unsigned int pos = 0;    unsigned int j = 0;    while(j < numVec.size())    {        result.push_back(oddVec[pos]);        ++ j;        if(j == numVec.size())            break;        result.push_back(evenVec[pos]);        ++ j;        ++ pos;    }    return result;}int main(){    string str;    vector<int> numVec;    vector<int> result;    getline(cin, str);    numVec = splitStr(str, " ");    result = sortVec(numVec);    for(unsigned int i = 0; i < result.size(); i++)        cout << result[i] << " ";    cout << endl;    return 0;}