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🐛 PHP — Learn From Zero

Playground: Replit PHP | JDoodle — click, type, run.

What is PHP?

PHP is a server-side scripting language built for the web. It powers WordPress, Laravel, and ~75% of websites with a backend.

  • Web backends & CMS (WordPress)
  • APIs (Laravel, Symfony)
  • Dynamic page generation
  • Quick prototyping

Run Online — No Install

Use the playground links above.

🟢 Beginner — Core Basics

Your First Program

php

PHP code goes inside <?php ?>.

Variables

php
$name = "Ada";
$age = 36;
$height = 1.78;
$isStudent = true;

Variables start with $.

If / Else

php
$age = 18;
if ($age >= 18) echo "Vote";
else echo "Too young";

Use elseif for chains.

Loops

php
for ($i = 0; $i < 5; $i++) echo $i;
foreach ([1,2,3] as $n) echo $n;

foreach is great for arrays.

Functions

php
function greet($name) {
  return "Hello, $name!";
}

Strings interpolate variables directly.

Arrays

php
$fruits = ["apple", "banana"];
$fruits[] = "cherry";
$person = ["name" => "Ada", "age" => 36];

Arrays are ordered maps in PHP.

🟡 Intermediate — Building Real Programs

Forms & GET/POST

php
if ($_SERVER["REQUEST_METHOD"] === "POST") {
  echo $_POST["name"];
}

Read input via $_GET/$_POST.

Classes

php
class Person {
  public $name;
  function __construct($n) { $this->name = $n; }
}

Use $this for instance.

Database (PDO)

php
$pdo = new PDO($dsn, $u, $p);
$stmt = $pdo->prepare("SELECT * FROM users WHERE id = ?");
$stmt->execute([1]);

Always prepare statements (SQL injection).

Namespaces

php
namespace App\Models;
class User {}

Organize code in namespaces.

Composer

php
{
  "require": { "monolog/monolog": "^3.0" }
}

PHP dependency manager.

🔴 Advanced — Pro Concepts

Traits

php
trait Logger { function log($m) { echo $m; } }
class A { use Logger; }

Reuse methods across classes.

Closures

php
$fn = function($x) { return $x * 2; };
echo $fn(5);

Anonymous functions with use.

Generators

php
function nums() { for ($i=0;;$i++) yield $i; }

Lazy iteration with yield.

Attributes (PHP 8)

php
#[Route("/home")]
class HomeController {}

Native annotations via attributes.

What's Next?

  • Build a tiny project: Calculator, To-Do App, Weather Widget
  • Read the official docs and a good book
  • Solve Exercism exercises
  • Join a community & share your code

Practice daily for 20 minutes. Consistency > intensity.