How to Search by key=value in a Multidimensional Array in PHP

In PHP, searching for a specific keyvalue pair in a multidimensional array is a common requirement when working with complex data structures. There are several effective approaches to accomplish this task.

Here are three commonly used approaches ?

• Using a foreach loop

• Using array_filter() and array_column()

• Using array_search() with array_column()

Using a foreach loop

The foreach loop provides a straightforward way to iterate through each subarray and check for the desired keyvalue pair ?

<?php
$users = [
    ['id' => 1, 'name' => 'John', 'city' => 'New York'],
    ['id' => 2, 'name' => 'Jane', 'city' => 'London'],
    ['id' => 3, 'name' => 'Bob', 'city' => 'New York']
];

$searchKey = 'city';
$searchValue = 'New York';
$foundElement = null;

foreach ($users as $user) {
    if (isset($user[$searchKey]) && $user[$searchKey] === $searchValue) {
        $foundElement = $user;
        break;
    }
}

if ($foundElement !== null) {
    echo "Found: " . $foundElement['name'] . " from " . $foundElement['city'];
} else {
    echo "No match found";
}
?>

Found: John from New York

Using array_filter() and array_column()

The array_filter() function allows you to filter the array based on a callback function, returning all matching elements ?

<?php
$products = [
    ['id' => 1, 'category' => 'electronics', 'price' => 100],
    ['id' => 2, 'category' => 'books', 'price' => 25],
    ['id' => 3, 'category' => 'electronics', 'price' => 200]
];

$searchKey = 'category';
$searchValue = 'electronics';

$result = array_filter($products, function ($product) use ($searchKey, $searchValue) {
    return isset($product[$searchKey]) && $product[$searchKey] === $searchValue;
});

if (!empty($result)) {
    echo "Found " . count($result) . " electronic products:
";
    foreach ($result as $product) {
        echo "ID: " . $product['id'] . ", Price: $" . $product['price'] . "
";
    }
} else {
    echo "No matches found";
}
?>

Found 2 electronic products:
ID: 1, Price: $100
ID: 3, Price: $200

Using array_search() with array_column()

This approach extracts a column of values and searches for the first match using array_search() ?

<?php
$employees = [
    ['id' => 101, 'name' => 'Alice', 'department' => 'HR'],
    ['id' => 102, 'name' => 'Bob', 'department' => 'IT'],
    ['id' => 103, 'name' => 'Carol', 'department' => 'Finance']
];

$searchKey = 'department';
$searchValue = 'IT';
$key = array_search($searchValue, array_column($employees, $searchKey));

if ($key !== false) {
    echo "Found employee: " . $employees[$key]['name'] . " in " . $employees[$key]['department'];
} else {
    echo "No employee found in that department";
}
?>

Found employee: Bob in IT

Comparison

Conclusion

Each approach has its advantages depending on your needs. Use foreach for custom logic, array_filter() for multiple matches, and array_search() with array_column() for quick singleresult searches.