PhP：合并具有匹配键的数组并删除/删除额外的不匹配值

I'd like to merge these two arrays based on their key, and only keep the key matches. The merged array should retain the key, and the value should come from the second array.

Array #1: States I've Visited

Array
(
    [AL] => 113
    [AZ] => 83
    [CA] => 50
    [CO] => 1
...

Array #2: All States

Array
(
    [AL] => ALABAMA
    [AK] => ALASKA
    [AZ] => ARIZONA
    [AR] => ARKANSAS
    [CA] => CALIFORNIA
    [CO] => COLORADO
    [CT] => CONNECTICUT
...

So, If I've been to a state, I'd like to get the name of that state from Array 2. And throw out any non-matching nodes from array #2.

Desired Result

Array
(
    [AL] => ALABAMA
    [AZ] => ARIZONA
    [CA] => CALIFORNIA
    [CO] => COLORADO
...

I've done extensive research in the PHP manual and on StackOverflow, and cannot find a particular answer to this. I think it probably lies in a more complex user defined function than I am capable of at this point.

array_merge() almost does what I want, but then it adds the states I have not visited to the end of the array

array_intersect_key() also gets close. It keeps only the matching keys, but then it gets rid of values.

Enjoy this mildly inefficient example while I write a better solution. http://codepad.org/hIjPEM81

Inefficient Solution 1:

<?php
$allstates=array("MO"=>"Missouri", "TX"=>"Texas");
$statesIveBeenTo = array("MO"=>1);
foreach($allstates as $k=>$v){
  if(!array_key_exists($k,$statesIveBeenTo)){
    unset($allstates[$k]);
  }
}

var_dump($allstates);

Outputs:

array(1) {
  ["MO"]=>
  string(8) "Missouri"
}

Solution 2:

$test = array_intersect_key($allstates, $statesIveBeenTo);
var_dump($test);

The same output as above.