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# PHP Cheatsheet

PHP is a server-side scripting language used for web development. It provides features such as dynamic typing, arrays, functions, loops, conditionals, and file manipulation to help developers build dynamic and interactive web applications. This cheatsheet provides an overview of some of the key features of PHP, along with code blocks for variables, functions, loops, conditionals, file manipulation, and resources for further learning.

## Variables

// Declaring a variable

$myString = 'Hello, World!';

$myNumber = 42;

$myBoolean = true;

// Concatenating strings

$fullName = $firstName . ' ' . $lastName;

// Variable scope

function myFunction() {

global $myVariable; // Accessing a global variable

$localVariable = 'Local variable'; // Declaring a local variable

}

## Functions

// Declaring a function

function addNumbers($a, $b) {

return $a + $b;

}

// Declaring a function with default parameters

function sayHello($name = 'World') {

echo 'Hello, ' . $name . '!';

}

// Declaring a function with variable arguments

function sum(...$numbers) {

return array_sum($numbers);

}

// Declaring an anonymous function

$myFunction = function($param) {

// function body

};

## Loops

// for loop

for ($i = 0; $i < 10; $i++) {

echo $i;

}

// foreach loop

$myArray = array(1, 2, 3, 4, 5);

foreach ($myArray as $item) {

echo $item;

}

// while loop

$i = 0;

while ($i < 10) {

echo $i;

$i++;

}

// do...while loop

$j = 0;

do {

echo $j;

$j++;

} while ($j < 10);

## Conditionals

// if statement

if ($myNumber === 42) {

echo 'The answer to the ultimate question of life, the universe, and everything';

}

// if...else statement

if ($myBoolean) {

echo 'The boolean is true';

} else {

echo 'The boolean is false';

}

// ternary operator

$result = $myNumber > 0 ? 'Positive' : 'Negative or zero';

// switch statement

switch ($myString) {

case 'Hello':

echo 'The string is "Hello"';

break;

case 'World':

echo 'The string is "World"';

break;

default:

echo 'The string is something else';

break;

}

## File manipulation

// Including a file

include 'myfile.php';

// Requiring a file

require 'myfile.php';

// Reading a file

$myfile = fopen('myfile.txt', 'r');

echo fread($myfile, filesize('myfile.txt'));

fclose($myfile);

// Writing to a file

$myfile = fopen('myfile.txt', 'w');

fwrite($myfile, 'Hello, World!');

fclose($myfile);

## Resources

- [PHP documentation](https://www.php.net/manual/en/index.php)
- [PHP tutorial](https://www.w3schools.com/php/)
- [PHP with MySQL tutorial](https://www.w3schools.com/php/php_mysql_intro.asp)
- [Laravel framework](https://laravel.com/)
- [Symfony framework](https://symfony.com/)