Sort Array of Objects by Object Fields in PHP

In PHP, you can sort an array of objects by their properties using several built-in functions. Each approach offers different advantages depending on your specific requirements and coding style preferences.

Using usort() Function with a Custom Comparison Function

The usort() function provides the most flexible approach for sorting objects by custom logic ?

<?php
class Person {
    public $name;
    public $age;
    
    public function __construct($name, $age) {
        $this->name = $name;
        $this->age = $age;
    }
}

// Create array of objects
$people = [
    new Person("Alice", 30),
    new Person("Bob", 25),
    new Person("Charlie", 35)
];

// Custom comparison function
function compareByAge($a, $b) {
    return $a->age <=> $b->age;
}

// Sort the array using the custom comparison function
usort($people, 'compareByAge');

// Display sorted results
foreach ($people as $person) {
    echo $person->name . " - " . $person->age . "<br>";
}
?>

Bob - 25
Alice - 30
Charlie - 35

Using Anonymous Functions

You can also use anonymous functions for more concise code ?

<?php
class Product {
    public $name;
    public $price;
    
    public function __construct($name, $price) {
        $this->name = $name;
        $this->price = $price;
    }
}

$products = [
    new Product("Laptop", 999.99),
    new Product("Mouse", 25.50),
    new Product("Keyboard", 75.00)
];

// Sort by price using anonymous function
usort($products, function($a, $b) {
    return $a->price <=> $b->price;
});

foreach ($products as $product) {
    echo $product->name . " - $" . $product->price . "<br>";
}
?>

Mouse - $25.5
Keyboard - $75
Laptop - $999.99

Utilizing the array_multisort() Function

For simple field-based sorting, array_multisort() combined with array_column() provides an efficient solution ?

<?php
// Convert objects to associative arrays for array_column
$students = [
    (object)["name" => "John", "grade" => 85],
    (object)["name" => "Sarah", "grade" => 92],
    (object)["name" => "Mike", "grade" => 78]
];

// Extract grades for sorting
$grades = array_column($students, 'grade');

// Sort by grades in descending order
array_multisort($grades, SORT_DESC, $students);

foreach ($students as $student) {
    echo $student->name . " - " . $student->grade . "<br>";
}
?>

Sarah - 92
John - 85
Mike - 78

Comparison

Conclusion

Use usort() for complex sorting requirements and custom logic. For simple field-based sorting, array_multisort() with array_column() offers better performance and cleaner code.