How to form a loop through an array?

Question

PHP

It is necessary to display cities and abbreviations in select, and, as it were, a path from one city to another.
How it should look like. How to take next() and write it down, chtoli? I hope someone will tell you what realties is not cumbersome option

<select name="" id="">
 <option value="HRK">HRK</option>
 <option value="HRK->KHE">HRK->KHE</option>
 <option value="KHE">KHE</option>
 <option value="KHE->ODS">KHE->ODS</option>
 <option value="LVO">LVO</option>
 <option value="LVO->ODS">LVO->ODS</option>
<option value="ODS">ODS</option>
</select>

array:4 [▼
  0 => array:5 [▼
    "id" => 3
    "name" => "HRK"
    "city" => "KHARKIV"
  ]
  1 => array:5 [▼
    "id" => 6
    "name" => "KHE"
    "city" => "KHERSON"
  ]
  2 => array:5 [▼
    "id" => 7
    "name" => "LVO"
    "city" => "LVOV"
  ]
  3 => array:5 [▼
    "id" => 4
    "name" => "ODS"
    "city" => "ODESA"
  ]
]

Answer 1

It can be something like this:

$last_city = ''; // initial empty value
foreach($cities as $city) {
  if ($last_city != '') { // if value not empty show transit option
    echo '<option value="'.$last_city.'-'.$city['name'].'">'.$last_city.'-'.$city['name'].'</option>'. PHP_EOL;
  }
  echo '<option value="'.$city['name'].'">'.$city['name'].'</option>' . PHP_EOL;
  $last_city = $city['name']; // store value for next iteration
}

Check PHP code here