Essential advanced skills for PHP interviews

PHP advanced technologies include: magic methods (handling events), generators (effectively traversing collections), closures (passing anonymous functions), anonymous classes (quickly creating classes), and attributes (adding methods and properties). Practical case: Use a generator to create a pager and obtain a large number of data collections in batches.

Essential advanced skills for PHP interviews

1. Magic methods

Magic methods allow you to handle specific events within a class. For example, the __construct() method is used to initialize the object, while the __destruct() is used to release resources.

class MyClass {
    public function __construct() {
        // 对象初始化代码
    }
    
    public function __destruct() {
        // 清理代码
    }
}

2. Generators

Generators are an efficient way to iterate over a collection without loading the entire collection at once.

function numbers() {
    for ($i = 0; $i < 10; $i++) {
        yield $i;
    }
}

foreach (numbers() as $number) {
    echo $number;
}

3. Closure

A closure is an anonymous function passed as a parameter. They are used to bind functions to variables or objects.

$greeting = function($name) {
    return "Hello, $name!";
};

echo $greeting("John"); // Hello, John!

4. Anonymous classes

Anonymous classes allow you to quickly create classes without defining a class name.

$object = new class {
    public function greet($name) {
        return "Hello, $name!";
    }
};

echo $object->greet("Jane"); // Hello, Jane!

5. Attributes

Attributes allow you to add methods and properties to existing classes without inheritance.

trait Greeting {
    public function greet($name) {
        return "Hello, $name!";
    }
}

class MyClass {
    use Greeting;
}

$object = new MyClass();
echo $object->greet("Alice"); // Hello, Alice!

Practical case: Using a generator to create a pager

function paginate($data, $perPage) {
    $currentPage = 1;

    while ($currentPage <= ceil(count($data) / $perPage)) {
        $offset = ($currentPage - 1) * $perPage;
        yield array_slice($data, $offset, $perPage);
        $currentPage++;
    }
}

$data = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10];

foreach (paginate($data, 3) as $page) {
    print_r($page);
}

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