getting bordering US states (php)

Question

HI need to be able to select a state and be given a list of the bordering states. Does anyone have or know of code already done for this?

If I have to write it myself, what would be the best way - possibly a mysql database of borders (two state columns for each row), and then select matching?

EDIT: here's a start - list of borders: http://www.econ.umn.edu/~holmes/data/BORDLIST.html

Answer 1

<?php
$borders = array (
  'AL' => 
  array (
    0 => 'FL',
    1 => 'GA',
    2 => 'MS',
    3 => 'TN',
  ),
  'FL' => 
  array (
    0 => 'AL',
    1 => 'GA',
  ),
  'GA' => 
  array (
    0 => 'AL',
    1 => 'FL',
    2 => 'NC',
    3 => 'SC',
    4 => 'TN',
  ),
  'MS' => 
  array (
    0 => 'AL',
    1 => 'AR',
    2 => 'LA',
    3 => 'TN',
  ),
  'TN' => 
  array (
    0 => 'AL',
    1 => 'AR',
    2 => 'GA',
    3 => 'KY',
    4 => 'MO',
    5 => 'MS',
    6 => 'NC',
    7 => 'VA',
  ),
  'AR' => 
  array (
    0 => 'LA',
    1 => 'MO',
    2 => 'MS',
    3 => 'OK',
    4 => 'TN',
    5 => 'TX',
  ),
  'LA' => 
  array (
    0 => 'AR',
    1 => 'MS',
    2 => 'TX',
  ),
  'MO' => 
  array (
    0 => 'AR',
    1 => 'IA',
    2 => 'IL',
    3 => 'KS',
    4 => 'KY',
    5 => 'NE',
    6 => 'OK',
    7 => 'TN',
  ),
  'OK' => 
  array (
    0 => 'AR',
    1 => 'CO',
    2 => 'KS',
    3 => 'MO',
    4 => 'NM',
    5 => 'TX',
  ),
  'TX' => 
  array (
    0 => 'AR',
    1 => 'LA',
    2 => 'NM',
    3 => 'OK',
  ),
  'AZ' => 
  array (
    0 => 'CA',
    1 => 'CO',
    2 => 'NM',
    3 => 'NV',
    4 => 'UT',
  ),
  'CA' => 
  array (
    0 => 'AZ',
    1 => 'NV',
    2 => 'OR',
  ),
  'CO' => 
  array (
    0 => 'AZ',
    1 => 'KS',
    2 => 'NE',
    3 => 'NM',
    4 => 'OK',
    5 => 'UT',
    6 => 'WY',
  ),
  'NM' => 
  array (
    0 => 'AZ',
    1 => 'CO',
    2 => 'OK',
    3 => 'TX',
    4 => 'UT',
  ),
  'NV' => 
  array (
    0 => 'AZ',
    1 => 'CA',
    2 => 'ID',
    3 => 'OR',
    4 => 'UT',
  ),
  'UT' => 
  array (
    0 => 'AZ',
    1 => 'CO',
    2 => 'ID',
    3 => 'NM',
    4 => 'NV',
    5 => 'WY',
  ),
  'OR' => 
  array (
    0 => 'CA',
    1 => 'ID',
    2 => 'NV',
    3 => 'WA',
  ),
  'KS' => 
  array (
    0 => 'CO',
    1 => 'MO',
    2 => 'NE',
    3 => 'OK',
  ),
  'NE' => 
  array (
    0 => 'CO',
    1 => 'IA',
    2 => 'KS',
    3 => 'MO',
    4 => 'SD',
    5 => 'WY',
  ),
  'WY' => 
  array (
    0 => 'CO',
    1 => 'ID',
    2 => 'MT',
    3 => 'NE',
    4 => 'SD',
    5 => 'UT',
  ),
  'CT' => 
  array (
    0 => 'MA',
    1 => 'NY',
    2 => 'RI',
  ),
  'MA' => 
  array (
    0 => 'CT',
    1 => 'NH',
    2 => 'NY',
    3 => 'RI',
    4 => 'VT',
  ),
  'NY' => 
  array (
    0 => 'CT',
    1 => 'MA',
    2 => 'NJ',
    3 => 'PA',
    4 => 'VT',
  ),
  'RI' => 
  array (
    0 => 'CT',
    1 => 'MA',
  ),
  'DC' => 
  array (
    0 => 'MD',
    1 => 'VA',
  ),
  'MD' => 
  array (
    0 => 'DC',
    1 => 'DE',
    2 => 'PA',
    3 => 'VA',
    4 => 'WV',
  ),
  'VA' => 
  array (
    0 => 'DC',
    1 => 'KY',
    2 => 'MD',
    3 => 'NC',
    4 => 'TN',
    5 => 'WV',
  ),
  'DE' => 
  array (
    0 => 'MD',
    1 => 'NJ',
    2 => 'PA',
  ),
  'NJ' => 
  array (
    0 => 'DE',
    1 => 'NY',
    2 => 'PA',
  ),
  'PA' => 
  array (
    0 => 'DE',
    1 => 'MD',
    2 => 'NJ',
    3 => 'NY',
    4 => 'OH',
    5 => 'WV',
  ),
  'NC' => 
  array (
    0 => 'GA',
    1 => 'SC',
    2 => 'TN',
    3 => 'VA',
  ),
  'SC' => 
  array (
    0 => 'GA',
    1 => 'NC',
  ),
  'IA' => 
  array (
    0 => 'MN',
    1 => 'MO',
    2 => 'NE',
    3 => 'SD',
    4 => 'WI',
    5 => 'IL',
  ),
  'MN' => 
  array (
    0 => 'IA',
    1 => 'ND',
    2 => 'SD',
    3 => 'WI',
  ),
  'SD' => 
  array (
    0 => 'IA',
    1 => 'MN',
    2 => 'MT',
    3 => 'ND',
    4 => 'NE',
    5 => 'WY',
  ),
  'WI' => 
  array (
    0 => 'IA',
    1 => 'IL',
    2 => 'MI',
    3 => 'MN',
  ),
  'ID' => 
  array (
    0 => 'MT',
    1 => 'NV',
    2 => 'OR',
    3 => 'UT',
    4 => 'WA',
    5 => 'WY',
  ),
  'MT' => 
  array (
    0 => 'ID',
    1 => 'ND',
    2 => 'SD',
    3 => 'WY',
  ),
  'WA' => 
  array (
    0 => 'ID',
    1 => 'OR',
  ),
  'IL' => 
  array (
    0 => 'IA',
    1 => 'IN',
    2 => 'KY',
    3 => 'MO',
    4 => 'WI',
  ),
  'IN' => 
  array (
    0 => 'IL',
    1 => 'KY',
    2 => 'MI',
    3 => 'OH',
  ),
  'KY' => 
  array (
    0 => 'IL',
    1 => 'IN',
    2 => 'MO',
    3 => 'OH',
    4 => 'TN',
    5 => 'VA',
    6 => 'WV',
  ),
  'MI' => 
  array (
    0 => 'IN',
    1 => 'OH',
    2 => 'WI',
  ),
  'OH' => 
  array (
    0 => 'IN',
    1 => 'KY',
    2 => 'MI',
    3 => 'PA',
    4 => 'WV',
  ),
  'WV' => 
  array (
    0 => 'KY',
    1 => 'MD',
    2 => 'OH',
    3 => 'PA',
    4 => 'VA',
  ),
  'NH' => 
  array (
    0 => 'MA',
    1 => 'ME',
    2 => 'VT',
  ),
  'VT' => 
  array (
    0 => 'MA',
    1 => 'NH',
    2 => 'NY',
  ),
  'ME' => 
  array (
    0 => 'NH',
  ),
  'ND' => 
  array (
    0 => 'MN',
    1 => 'MT',
    2 => 'SD',
  ),
);

echo "Illinois borders: \n";
foreach ($borders['IL'] as $s)
  echo "\t$s\n";