How to loop through arrays of arrays in PHP - php

Question

I'd like to take an array with this structure:
array
'Alabama' =>
array
0 =>
array
'id' => string '11' (length=2)
'region_name' => string 'Alabama' (length=7)
'city' => string 'Birmingham' (length=10)
1 =>
array
'id' => string '12' (length=2)
'region_name' => string 'Alabama' (length=7)
'city' => string 'Huntsville' (length=10)
2 =>
array
'id' => string '13' (length=2)
'region_name' => string 'Alabama' (length=7)
'city' => string 'Mobile' (length=6)
3 =>
array
'id' => string '14' (length=2)
'region_name' => string 'Alabama' (length=7)
'city' => string 'Montgomery' (length=10)
'Alaska' =>
array
0 =>
array
'id' => string '15' (length=2)
'region_name' => string 'Alaska' (length=6)
'city' => string 'Anchorage' (length=9)
And create unordered lists in html, like so:
<ul id="A">
<li class="state">Alabama</li>
<li>Birmingham</li>
<li>Huntsville</li>
<li>Mobile</li>
<li>Montgomery</li>
<li class="state">Alaska</li>
<li>Anchorage</li>
</ul>
<ul id="C">
<li class="state">California</li>
<li>Bakersfield</li>
<li>Fresno</li>
<li>Los Angeles</li>
</ul>
<ul id="D">
<li class="state">DC</li>
<li>Washington</li>
</ul>
The idea is an alphabetically ordered and grouped series of unordered lists, which I can show and hide easily using javascript. That part is easy... This part, I'm lost.
I've tried a sort of nested foreach loop, but the framework I'm using refused to do it citing OutputEscaper errors, which I believe made sense - I really am not sure how to do this properly.
I'd appreciate any help!
edit: Here's how the array is initially formatted:
$this->cityGroups = array();
foreach($this->USCities as $city)
{
$this->cityGroups[$city['region_name']][] = $city;
}

Answer 1

This is simple and it doesn't need a framework. If you data was formatted as I mentioned in my comment...
$data = array('Alabama' => array('Birmingham', 'Huntsville', 'Mobile', 'Montgomery'),
'Alaska' => array('Anchorage'));
ksort($data);
$formatted = array();
foreach($data as $state => $cities) {
$formatted[$state{0}][$state] = $cities;
}
foreach($formatted as $letter => $states) {
echo '<ul id="'.$letter.'">';
foreach($states as $state => $cities) {
sort($cities);
echo '<li class="state">'.$state.'</li>'
foreach($cities as $city) {
echo '<li>'.$city.'</li>';
}
}
echo '</ul>';
}

Answer 2

This solution should achieve what you're looking for:
$lastLetter = "A";
print( '<ul id="A">' );
foreach( $myArray as $key => $array ){
if( strtoupper( substr( $key, 0, 1 ) ) != $lastLetter ){
print( '</ul>' );
$lastLetter = strtoupper( substr( $key, 0, 1 ) );
print( '<ul id="' . $lastLetter . '">' );
}
print( '<li class="state">' . $key . '</li>' );
foreach( $array as $subArr ){
print( '<li>' . $subArr['city'] . '</li>' );
}
}
print( '</ul>' );
If you need an explanation on any specific part, please let me know.
Alternate Solution, in the event your starting letter is variable (may or may not be A)
Change:
$lastLetter = "A";
print( '<ul id="A">' );
to:
$temp = array_keys( $myArray );
$lastLetter = strtoupper( substr( $temp[0], 0, 1 ) );
print( '<ul id="' . $lastLetter . '">' );