Learn PHP

PHP Topics

Click on a topic to expand and learn in detail.

• 1. Introduction to PHP

PHP is a server-side scripting language used to build dynamic websites.

<?php
echo "Hello World";
?>
      

• 2. Variables & Data Types

$name = "Alice";
$age = 25;

// Data types: string, int, float, bool, array, object, null
      

• 3. Operators

// Arithmetic: +, -, *, /, %
$sum = 5 + 3;

// Comparison: ==, !=, >, <
$result = (5 > 3);

// Logical: &&, ||, !
$flag = true && false;
      

• 4. Conditions (if, else, switch)

$age = 18;

if($age >= 18){
    echo "Adult";
}else{
    echo "Minor";
}

switch($age){
    case 18:
        echo "Exactly 18";
        break;
    default:
        echo "Other";
}
      

• 5. Loops (for, while, do-while, foreach)

// for loop
for($i=0; $i<5; $i++){
    echo $i;
}

// while loop
$i=0;
while($i<5){
    echo $i;
    $i++;
}

// do-while loop
$j=0;
do{
    echo $j;
    $j++;
}while($j<5);

// foreach (arrays)
$fruits = array("Apple","Banana","Mango");
foreach($fruits as $fruit){
    echo $fruit;
}
      

• 6. Functions

function greet($name){
    return "Hello ".$name;
}

echo greet("Alice");

// Anonymous function
$add = function($a,$b){ return $a+$b; };
echo $add(5,3);
      

• 7. Arrays

$fruits = array("Apple","Banana","Mango");
echo $fruits[0]; // Apple

// Associative array
$person = array("name"=>"Alice","age"=>25);
echo $person["name"];
      

• 8. Strings & String Functions

$text = "Hello World";
echo strtoupper($text); // HELLO WORLD
echo strtolower($text); // hello world
echo str_replace("World","PHP",$text); // Hello PHP
      

• 9. Forms & User Input

<form method="post" action="process.php">
    Name: <input type="text" name="name">
    <input type="submit">
</form>

<?php
$name = $_POST['name'];
echo "Hello ".$name;
?>
      

• 10. File Handling

<?php
// Write to file
$file = fopen("data.txt","w");
fwrite($file,"Hello PHP");
fclose($file);

// Read file
$file = fopen("data.txt","r");
echo fread($file,filesize("data.txt"));
fclose($file);
?>
      

• 11. Database (MySQL) & PDO

<?php
$host = "localhost";
$db = "test";
$user = "root";
$pass = "";

// Using PDO
try{
    $conn = new PDO("mysql:host=$host;dbname=$db",$user,$pass);
    $conn->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
    echo "Connected Successfully";
}catch(PDOException $e){
    echo "Connection failed: ".$e->getMessage();
}
?>
      

• 12. Advanced PHP Topics
• Sessions & Cookies
• Object-Oriented PHP (Classes, Objects, Inheritance)
• PHP Namespaces
• PHP Exceptions
• Working with JSON & APIs
• PHP Regular Expressions
• File Uploads & Security
• Composer & Package Management
• PHP MVC Framework Basics