搜索PHP数组值并显示它们（如果存在）

Question

I have two pages, an HTML, and PHP page. The HTML contains a form that asks a user to type a City name and how they want to sort it (none, ascending, or descending). The PHP page receives the input and contains an array of cities. My question is: how can I display the values (using a loop) that exist in the array if the input contains part of the string? Ex: if I search "De", it should return Detroit and Dearborn and sort them based on how I choose.

Here is the php code:

<?php
        $sort = substr(filter_input(INPUT_GET, 'sort', FILTER_SANITIZE_STRING),0,4);
        $city = substr(filter_input(INPUT_GET, 'city', FILTER_SANITIZE_STRING),0,20);
          $cities[0] = "Detroit, Michigan";
          $cities[1] = "Rome, Italy";
          $cities[2] = "New York, New York";
          $cities[3] = "Austin, Texas";
          $cities[4] = "Atlanta, Georgia";
          $cities[5] = "Dubai, UAE";
          $cities[6] = "Shanghai, China";
          $cities[7] = "Mumbai, India";
          $cities[8] = "Windsor, Canada";
          $cities[9] = "Los Angeles, California";
          $cities[10] = "Chicago, Illinois";
          $cities[11] = "London, England";
          $cities[12] = "Dearborn, Michigan";
          $cities[13] = "Istanbul, Turkey";
          $cities[14] = "Pittsburgh, Pennsylvania";
          $cities[15] = "Cincinnati, Ohio";
          $cities[16] = "Anaheim, California";
          $cities[17] = "Orlando, Florida";
          $cities[18] = "Dallas, Texas";
          $cities[19] = "Hong Kong, China";
          $cities[20] = "Cairo, Egypt";
?>

Answer 1

array_filter() with a fnmatch() check seems a logical approach:

$matches = array_filter(
    $cities,
    function($value) use ($city) {
        return fnmatch('*'.$city.'*', $value, FNM_CASEFOLD);
    }
);

EDIT

Explanation... array_filter() executes the callback against each value in the array ($cities) and that callback returns a boolean true/false to indicate whether it should be accepted or discarded. The callback uses the fnmatch() function to execute a wildcard comparison against the array entry value against your search value; if the value matches, then it returns a true; else it returns a false.

The result; the $matches array contains only those entries that match your search criteria.

Demo

If you want the result ($matches) sorted; then sort it after running that filter

Answer 2

First, you can filter your cities with array_filter .

$filtered = array_filter($cities, function($current) use ($city) {
    // If the current city start with our input, we keep it.
    return stripos($current, $city) === 0;
});

Second, you can sort your cities with sort rsort depending of the order.

if ($sort === 'ASC') {
    sort($filtered);
} elseif ($sort === 'DESC') {
    rsort($filtered);
}

And then, you just have to return your filtered and ordered results.

Answer 3

You could loop over the array and use the PHP strstr function to find matches:

$matches = array();
foreach ($cities as $city) {
    if (strstr($city, $search)) {
        $matches[] = $city;
    }
}