php

PHP Language Tutorial

1. What is PHP?

PHP (Hypertext Preprocessor) is a server-side scripting language designed for web development. It is widely used to create dynamic and interactive web pages.

2. How to Install PHP?

1. Download the PHP binaries from the official PHP website or install using a package manager like apt or yum.
2. Configure your server to work with PHP (e.g., Apache, Nginx).
3. Verify the installation by running php -v in the terminal.

3. Your First PHP Script

Create a PHP file and add the following code:

<?php
    echo "Hello, World!";
?>

Save this file as hello.php and run it on your web server. Access it through your browser, e.g., http://localhost/hello.php.

4. Variables and Data Types

In PHP, variables are declared with a $ sign. Common data types include:

<?php
    $x = 10; // Integer
    $y = 3.14; // Float
    $name = "PHP"; // String
    $isAvailable = true; // Boolean

    echo "x = $x, y = $y, name = $name, isAvailable = $isAvailable";
?>

5. Conditional Statements

PHP supports if, else if, and else statements.

<?php
    $num = 10;
    if ($num > 0) {
        echo "Positive number";
    } elseif ($num == 0) {
        echo "Zero";
    } else {
        echo "Negative number";
    }
?>

6. Loops

PHP supports for, while, and foreach loops.

For Loop:

<?php
    for ($i = 0; $i < 5; $i++) {
        echo $i . "
";
    }
?>

While Loop:

<?php
    $count = 0;
    while ($count < 5) {
        echo $count . "
";
        $count++;
    }
?>

7. Functions

Functions in PHP allow for reusable code blocks.

<?php
    function greet($name) {
        echo "Hello, $name!";
    }

    greet("Alice");
?>

8. Arrays

Arrays in PHP can be indexed or associative.

<?php
    $numbers = [1, 2, 3, 4, 5];
    foreach ($numbers as $num) {
        echo $num . "
";
    }
?>

9. Object-Oriented PHP

PHP supports object-oriented programming.

<?php
    class Student {
        public $name;
        public $age;

        public function __construct($name, $age) {
            $this->name = $name;
            $this->age = $age;
        }

        public function displayInfo() {
            echo "Name: $this->name, Age: $this->age";
        }
    }

    $s1 = new Student("John", 21);
    $s1->displayInfo();
?>

10. File Handling

PHP makes file handling easy using built-in functions.

<?php
    $file = fopen("example.txt", "w");
    fwrite($file, "Hello, PHP!");
    fclose($file);

    $file = fopen("example.txt", "r");
    echo fgets($file);
    fclose($file);
?>

11. Sessions and Cookies

Sessions and cookies are used to store user data.

<?php
    session_start();
    $_SESSION["user"] = "John";
    echo "Session user: " . $_SESSION["user"];

    setcookie("user", "John", time() + (86400 * 30), "/");
    if (isset($_COOKIE["user"])) {
        echo "Cookie user: " . $_COOKIE["user"];
    }
?>

12. PHP Libraries and Frameworks

Popular PHP libraries and frameworks include:

• Composer: Dependency management.
• Laravel: Web application framework.
• Symfony: Framework and reusable components.
• Guzzle: HTTP client.