What Are the Most Common Php Functions in 2025?

In the ever-evolving landscape of web development, PHP continues to be a stalwart of server-side scripting. As of 2025, certain PHP functions remain indispensable across a wide range of applications. Whether you're developing a simple website or an enterprise-grade application, these functions are crucial for efficient PHP development.

1. array_filter()

A highly efficient way to filter elements of an array using a callback function. With the growing complexity of data manipulation in 2025, array_filter() remains an essential tool for developers.

$array = [1, 2, 3, 4, 5];
$result = array_filter($array, function($value) {
    return $value % 2 == 0;
});

2. json_encode() and json_decode()

Handling JSON data is more critical than ever, especially when working with APIs and microservices. These two functions play a pivotal role in encoding and decoding JSON data, ensuring seamless data interchange.

$array = ['name' => 'John', 'age' => 30];
$json = json_encode($array);
$data = json_decode($json, true);

3. mysqli_connect()

Database connectivity is a fundamental requirement, and mysqli_connect() continues to be a popular choice for connecting to MySQL databases. It offers improved security and functionality compared to the older mysql_connect().

$conn = mysqli_connect("localhost", "username", "password", "database");

4. filter_var()

As security remains a top priority in 2025, filter_var() is indispensable for sanitizing user inputs. It helps prevent common vulnerabilities like XSS and SQL injection.

$email = "user@example.com";
if (filter_var($email, FILTER_VALIDATE_EMAIL)) {
    echo "This is a valid email address.";
}

5. strtotime()

Date and time manipulations are integral to many applications. strtotime() allows for flexible date parsing, making it easy to handle various date formats and calculations.

$date = strtotime("tomorrow");

6. Object-Oriented PHP Functions

With Object-Oriented Programming (OOP) increasingly becoming the norm, functions like __construct() and __destruct() are seen widely across many PHP applications. For a deeper dive into why OOP is essential in 2025, check out PHP OOP 2025.

7. include() and require()

These functions are critical for including files, making code modular and manageable. They ensure that scripts do not get cluttered and that components can be reused effortlessly.

include 'header.php'; 
require 'config.php';

By mastering these functions, developers can ensure their PHP applications are efficient, secure, and suited for any complex demands of 2025.

For anyone deciding on a framework, consider the CakePHP framework, favored for its robust set of features, while to enable testing, explore how to install PHPUnit with Composer.