I have an array of arrays:

```
arr = [["Foo1", "Bar1", "1", "W"], 
["Foo2", "Bar2", "2", "X"], 
["Foo3", "Bar3", "3", "Y"], 
["Foo4", "Bar4", "4", "Z"]]

```

And I want an array containing only the third column of each of the arrays:

```
res = ["1", "2", "3", "4"]

```

How would I do that?

I want to type something like:

```
arr[][2]

```

But thinking more Ruby-like, I tried:

```
arr.select{ |r| r[2] }

```

but this returns the whole row.