In practical development, the improvement of PHP performance not only depends on the optimization of the server environment,Language level optimization and code level optimizationIt is also crucial. Reasonably utilizing the language features and programming habits of PHP can enable you to write more efficient and maintainable code. Below are two dimensions for detailed analysis:

✅ 1、 Optimization at the PHP language level (based on syntax and mechanism itself)

one ️⃣ Use appropriate data structures

• Try to avoid sparse arrays when using them;

• Choose the appropriate array type (indexed array vs associative array);

• useset()Determine whether the array key exists, compared toarray_key_exists()Faster.

//Recommended
if (Eat($data['key'])) { ... }
//Be cautious (slow)
if (array_key_exists('key', $data)) { ... }

two ️⃣ Using type declarations (PHP 7+)

• Introducing strict types can reduce implicit conversion overhead;

• Using parameters and return valuesint, string, arrayClear declaration;

• Clear function signatures improve maintainability and execution efficiency.

declare(strict_types=1);
function add(int $a, int $b): int {
    return $a + $b;
}

three ️⃣ Avoid frequently calling magic methods

• Magic methods such as__get, __set, __callAlthough convenient, the performance is relatively low;

• Alternative solution: Use explicit methods or attribute access.

//Not recommended to frequently rely on __get/__set
class User {
    public $name;
}
//Recommend direct access to attributes
$user->name ='Tom';

four ️⃣ useinclude_once/require_oncecareful

• These functions always check whether the file is included, which is inefficient;

• If it is determined to only include once, it can be changed toincludeperhapsrequireCooperate with the automatic loader.

//Recommend using PSR-4 autoload mechanism or Composer autoload

five ️⃣ Using string concatenation to optimize performance

• When using double quotes, PHP will parse variables, consuming more resources;

• use.Better splicing performance, especially in large string scenarios.

//Not recommended
$str = "Hello$name";
//Recommended
$str = 'Hello ' . $name;

six ️⃣ Reduce function calls/database requests within the loop

• Remove unchanging calculations and requests from the loop;

• Batch database queries replace individual requests.

//  ❌ Inefficient writing style
foreach ($ids as $id) {
    $user = getUserById($id); //Every time the database is queried
}

//  ✅ Better writing style
$users = getUsersByIds($ids); //Batch query

✅ 2、 Code optimization techniques (at the level of program logic and structure)

one ️⃣ Reasonable use of caching mechanism

• Use APCu, Redis, or file caching for intermediate results;

• Page caching, data caching, and SQL result caching are all key to improving efficiency.

 $cacheKey = 'user_' . $userId;
if ($data = apcu_fetch( $cacheKey)) {
    return $data;
}
//Otherwise, retrieve from the database and write to the cache

two ️⃣ Delayed loading and lazy loading modes

• For large objects or database connections, it is recommended to delay initialization;

• It can reduce unnecessary resource expenses.

class User {
    private $profile;
    public function getProfile() {
        if ($this->profile ===null) {
            $this->profile =loadUserProfile();
        }
        return $this->profile; } }

three ️⃣ Avoid unnecessary object creation

• Try to reuse existing objects, especially in high concurrency scenarios;

• Static methods or factory patterns can reduce the number of instances.

four ️⃣ Using a generator to process large datasets（yield）

• Suitable for handling large amounts of files, database records, and other scenarios, saving memory.

function getLines($filename) {
    $file = open($filename, 'r');
    while ($line = fgets($file)) {
        yield $line;
    }
    fclose($file);
}

five ️⃣ Using precompiled OPcache

• Enable the OPcache extension for PHP to cache compiled bytecode;

• Improve response speed and reduce CPU usage.

Set in PHP.ini:

opcache.enable=1
opcache.memory_consumption=128
opcache.interned_strings_buffer=8
opcache.max_accelerated_files=4000

✅ 3、 Suggestions for auxiliary tools