Filter even numbers in a list; fork it for maximum fun!

gistfile1.txt

#these are meant to be run in a REPL, and the java one in beanshell of something of the sort:
#ruby
[1,2,3,4].select{ |x| x.even? }

#python
[x for x in [1,2,3,4] if not x%2]
#or, more norvingly
filter(lambda x: not x%2, [1,2,3,4])

#clojure
(filter #(even? % ) [1 2 3 4])
#but we don't need the wrapper (thanks to the guys in hackernews:)
(filter even? [1 2 3 4])

#scheme
(filter (lambda (x) (even? x)) '(1 2 3 4))
#same here:
(filter even? '(1 2 3 4))

#common lisp
(remove-if-not (lambda (x) (evenp x)) '(1 2 3 4))
#and here:
(remove-if-not 'evenp '(1 2 3 4))


#javascript
[1,2,3,4].filter(function(x){return !(x%2)})

#java
import java.util.ArrayList;
import java.util.Arrays;
public class filter {
    public static void main (String [] args)
    {
        Integer [] a = {1,2,3,4};

        System.out.println(
                    new ArrayList<Integer>(Arrays.asList(a)){{
                        ArrayList<Integer> clon = (ArrayList<Integer>)this.clone();
                        for(Integer e : clon){
                            if(e.intValue()%2 != 0)
                                this.remove(e);
                        }
                    }}
                );
    }
}

#After reading comments here and on HN, I now see that trying to *remove* stuff (filter-out) in hopes
#of mimicking how it _looks_ in other languages is stupid, even the lisps are actually building a new list
#recursively, so, here's a java version (which I took from the commments below) which is much more
#idiomatic and fair, as it accomplishes the same as the others: not using more than one explicit variable, #and that one, bound:

public class filter {
    public static void main (String [] args)
    {
        System.out.println(
                        new java.util.ArrayList(){{
                         for(Integer e : new Integer[]{1,2,3,4})
                            if(e%2 == 0) this.add(e);
                    }}
        );
    }
}

javascript 1.8

[1,2,3,4].filter(function (x) !(x%2))

Groovy

(1..4).findAll { !(it%2) }

(1..4).grep { !(it%2) }

C++

An improved C++ version:

#include <list>
#include <algorithm>
#include <iostream>
#include <iterator>


using namespace std;

int main (void)
{
    list<int> numbers = {1,2,3,4};
    remove_copy_if(numbers.begin(), numbers.end(), ostream_iterator<int>(cout, " "), [](int x) {return x % 2;});
}

Scala

  (1 to 4).filter(_ % 2 == 0)

Tcl

Tcl lacks a built-in filter function, but it is easy to write:

proc filter {list script} {
   set res ""
   foreach e $list {if $script {lappend res $e}}
   return $res
}

Then you have:
filter {1 2 3 4 5} {($e & 1)==0}

More succinct C++ version

#include <algorithm>
#include <iostream>
#include <iterator>

using namespace std;

int main (void)
{
    int nums[] = {1,2,3,4};
    remove_copy_if(nums, nums + 4, ostream_iterator<int>(cout, " "), [](int x) {return x % 2;});
    return 0;
}

Oh, well:

Java:

Arrays.asList(1,2,3,4).stream().filter((i)-> i%2==0).collect(toList());

I have a problem in a loop while compiling this code giving error in this portion