Taking single numeric key array and sorting by multi-dimensions.

[alturic]

I have an array like so:

array (
  0 => 
  array (
    'zipcode' => '18640',
    'latitude' => '41.31390',
    'longitude' => '-75.77767',
    'state' => 'Pennsylvania',
    'county' => 'Luzerne',
    'city' => 'Pittston',
  ),
  1 => 
  array (
    'zipcode' => '18515',
    'latitude' => '41.44901',
    'longitude' => '-75.66408',
    'state' => 'Pennsylvania',
    'county' => 'Lackawanna',
    'city' => 'Scranton',
  ),
  2 => 
  array (
    'zipcode' => '18704',
    'latitude' => '41.27534',
    'longitude' => '-75.89115',
    'state' => 'Pennsylvania',
    'county' => 'Luzerne',
    'city' => 'Kingston',
  ),
  3 => 
  array (
    'zipcode' => '90210',
    'latitude' => '34.08476',
    'longitude' => '-118.40629',
    'state' => 'California',
    'county' => 'Los Angeles',
    'city' => 'Beverly Hills',
  ),
  4 => 
  array (
    'zipcode' => '95456',
    'latitude' => '39.26767',
    'longitude' => '-123.75502',
    'state' => 'California',
    'county' => 'Mendocino',
    'city' => 'Little River',
  ),
  5 => 
  array (
    'zipcode' => '98499',
    'latitude' => '47.16618',
    'longitude' => '-122.50846',
    'state' => 'Washington',
    'county' => 'Pierce',
    'city' => 'Lakewood',
  ),
)

and I'm looking to use it to populate a drop-down like so:

 

Pennsylvania (state)

 -Luzerne (county)

  --18640

  --18702

 -Lackawanna (county)

  --18515

 

California

 -Mendocino

  --95456

 -Pierce

  --98499

 

So, I thought if this was accomplished with nested foreach's I'd do something like:

echo '<select>';
foreach ($zipcode as $singlestate) {
  echo '<option id='.$singlestate.'>';

    foreach ($singlestate as $singlecountinsinglestate) {
      echo '<option id='.$singlecountyinsinglestate.'>';

         foreach ($singlecountyinsinglestate as $individualzipcodes) {
           echo '<option id='.$individualzipcodes.'>';
         }

    }

}
echo '</select';

Which would end up looking like so:

<select>
<option id="California">California</option>
<option id="-Mendocino">-Mendocino</option>
<option id="--95456">--95456</option>
<option id="Pennsylvania">Pennsylvania</option>
<option id="-Luzerne">-Luzerne</option>
<option id="--18640">--18640</option>
<option id="--18702">--18702</option>
<option id="-Lackawanna">-Lackawanna</option>
<option id="--18515">--18515</option>
</select>

Of course, that entire idea wouldn't work if, in order to group the original array by State=>County=>ZIP, wasn't done using nested foreach's though... and frankly I can group by state, I can group by county but I get lost when I need to group by State=>County=>ZIP

 

[Jacques1]

<?php


$raw_data = ...;


$structured_data = [];

foreach ($raw_data as $entry)

{

    $structured_data[$entry['state']][$entry['county']][] = $entry['zipcode'];

}


var_dump($structured_data);

[alturic]

<?php

$raw_data = ...;

$structured_data = [];
foreach ($raw_data as $entry)
{
    $structured_data[$entry['state']][$entry['county']][] = $entry['zipcode'];
}

var_dump($structured_data);

 

Whoa, you just blew my mind....... :-/