this is my journey to learn and understand PHP
├── 📂 php-revision
├── 📂 src
|- 001_output.php
|- 002_variables.php
|- 003_arrays.php
|- 004_conditionals.php
|- 005_loops.php
|- 006_functions.php
|- 007_array_functions.php
|- 008_string_functions.php
|- 009_super_globals.php
|- 010_get_post.php
|- 011_sanitizing_inputs.php
|- 012_cookies.php
|- 013_sessions.php
|- 014_file_handling.php
|- 015_file_upload.php
|- 016_exception.php
|- 017_oop.php
docker-compose.yml
Dockerfile
README.md
- 000/folder-structure
Nothing much just basic folder structure
- php-revision/src/001_output.php
echomost common thing use for printing (specially for debugging) - withechoyou can print multiple values using as comma separated values - only string and numbersprintsame asechobut only print single valueprint_r()use a lot with arraysvar_dump()against use a lot with array but can use with anything - return type as wellvar_export()similar withvar_dump()but not as efficient asvar_dump()is<?= 'Some Text' ?>single line only - same asecho
<?php // This is a php tag. If there is no html or other content below the php, we don't need to close the php tag.
// echo 'hello World';
// // Single line comments
// /**
// * Multiline Comments
// */
// // You need semicolon at the send of every statement ';'
/* ------- Outputting Content ------- */
// // Echo - Output strings, numbers, html, etc
// echo 123, 'Hello', 10.5;
// // print - Similar to echo, but a bit slower
// print('Hello');
// // print_r - Gives a bit more info. Can be used to print arrays
// print_r('Hello');
// print_r([1, 2, 3]);
// // var_dump - Even more info like data type and length
// var_dump('Hello');
// var_dump([1, 2, 3]);
// // var_export - Similar to var_dump(). Output a string representation of a variable
// var_export('Hello');
?>
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>01_output</title>
</head>
<body>
<h1>
<?php echo 'Post One';?>
</h1>
<h1>
<?='Post Two' ?>
</h1>
</body>
</html>
- php-revision/src/002_variables.php
VariablesString- A string is a series of characters surrounded by quotesInteger- Whole numbersFloat- Decimal numbersBoolean- true or falseArray- An array is a special variable, which can hold more than one valueObject- A classNULL- Empty variableResource- A special variable that holds a resource
Data TypesVariablesmust be prefixed with $Variablesmust start with a letter or the underscore charactervariablescan't start with a numberVariablescan only contain alpha-numeric characters and underscores (A-z, 0-9, and _ )Variablesare case-sensitive ($name and $NAME are two different variables)
<?php
/* ----- Variables & Data Types ----- */
/* --------- PHP Data Types --------- */
/*
- String - A string is a series of characters surrounded by quotes
- Integer - Whole numbers
- Float - Decimal numbers
- Boolean - true or false
- Array - An array is a special variable, which can hold more than one value
- Object - A class
- NULL - Empty variable
- Resource - A special variable that holds a resource
*/
/* --------- Variable Rules --------- */
/*
- Variables must be prefixed with $
- Variables must start with a letter or the underscore character
- variables can't start with a number
- Variables can only contain alpha-numeric characters and underscores (A-z, 0-9, and _ )
- Variables are case-sensitive ($name and $NAME are two different variables)
*/
$name = "MAK"; // string
$age = 22; // int
$has_kids = false; // boolean
$has_on_hand = 100; // float
echo $name . "\t";
echo $age . "\t";
echo $has_kids . "\t";
echo $has_on_hand . "\t";
echo "<br />" . $name . ' is ' . $age . ' year old. and have ' . $has_on_hand . ' money'; // this is how you can do contact in php
echo "<br /> $name is $age year old. and have $has_on_hand money <br />"; // this is another way
$x = '5' + '5'; // php will still consider it as int;
var_dump($x);
echo "\t" . 10 - 5 . "\t";
echo 10 * 5 . "\t";
echo 10 / 5 . "\t";
echo 10 % 5 . "\t";
echo "<br />";
// constant
define('HOST', 'localhost'); // never change
echo HOST;
- php-revision/src/003_arrays.php
ArraysSimple Array- anything between two large brackets with a comma to separate them is a simple array.Associate Array- in associate array we will set key and value just like object in js.Multi Dimension Array- here we will have array inside another array
<?php
// Simple Array
$numbers = [1, 2, 3, 4, 5];
$fruits = array('apple', 'orange', 'banana');
print_r($numbers);
var_dump($fruits);
echo $fruits[1];
// Associate Array
$color = [
'black' => '#000',
'white' => '#fff'
];
echo $color['black'];
// Multi Dimension Array
$people = [
[
'first_name' => 'Moiz',
'last_name' => 'Ali',
'email' => 'some.email@cool.com'
],
[
'first_name' => 'Maria',
'last_name' => 'Khan',
'email' => 'some.email2@cool.com'
]
];
echo $people[1]['email'];
// convert an array into json
var_dump(json_encode($people));
- php-revision/src/04_conditionals.php
- If else
if (condition)- check if the statement is trueelseif (condition)- same as if check for second or more condition - optionalelse- this will run if no condition match - optional
- Ternary operator
?this is if statement-this is else?and-should run together&&this is and operator??this will check for first value and if not exist then go for second
- Switch cases
switch(condition)- switch case are same as if else here you start with passing the parameter then check if on every casecase value- check if provided value is same as parameterbreak- to break the switch casedefault- it will run if no other case match - optional
- If else
<?php
/* ---- Conditionals & Operators ---- */
/* ------------ Operators ----------- */
/*
< Less than
> Greater than
<= Less than or equal to
>= Greater than or equal to
== Equal to
=== Identical to
!= Not equal to
!== Not identical to
*/
/* ---------- If & If-Else Statements --------- */
/*
** If Statement Syntax
if (condition) {
// code to be executed if condition is true
}
*/
$age = 20;
if ($age > 18)
{
echo 'you are old enough' + "\n";
}
elseif ($age < 100) // elseif is adding a second or more conditions
{
echo 'too much old' + "\n";
}
else // else is a default which will run if no condition match
{
echo 'you are not old enough' + "\n";
}
$sports = ['Cricket'];
if (empty($sports)) // empty is a built in function to check is array is empty or not
{
echo 'no sports exist' + "\n";
}
/* -------- Ternary Operator -------- */
/*
The ternary operator is a shorthand if statement.
Ternary Syntax:
condition ? true : false;
*/
echo empty($sports) ? 'no sports exist' : $sports[0] + "\n";
echo empty($sports) && 'no sports exist' + "\n";
$first_post = $sports[0] ?? null; // ?? will check for first value if not exist add second value
/* -------- Switch Statements ------- */
$fav_color = 'red';
switch($fav_color) // switch case are same as if else here you start with passing the parameter then check if on every case
{
case 'red': // check if provided value is same as parameter
echo 'Your Favorite color is red';
break; // to break the switch case
case 'blue':
echo 'Your Favorite color is blue';
break;
default: // it will run if no other case match
echo 'I don\'t recognized your favorite color';
break;
}
?>
- php-revision/src/005_loop.php
for loopfor($a = 0; $a <= 10; $a++)- for loop have 3 parts - 1. initialize the variable - 2. add the condition (how much you want to run this loop) - 3. increment or decrement the value
while Loopwhile ($b <= 0)- same as for loop you put your condition and it will run until condition become true$b -= 1;- here we will pu increment or decrement
do while loopdo {}- in do while loop we perform the task first then check condition - in other words if you want to run condition at least one time use this$c++;- increment or decrementwhile ($c < 0);- checking the condition here
foreach loopforeach ($posts as $index => $post)- we use this for array - you can use above loops for arrays as well it just it more common to use - we can get index and individual value from the array using foreach
<?php
/* -------- Loops & Iteration ------- */
/* ------------ For Loop ------------ */
/*
** For Loop Syntax
for (initialize; condition; increment) {
// code to be executed
}
*/
echo "for loop start here" . "<br />" . "<br />";
for($a = 0; $a <= 10; $a++) // for loop have 3 parts - 1) initialize the variable - 2) add the condition (how much you want to run this loop) - 3) increment or decrement the value
{
echo $a . "<br />"; // do whatever you like here
}
echo "<br />" . "for loop ends here" . "<br />";
/* ------------ While Loop ------------ */
/*
** While Loop Syntax
while (condition) {
// code to be executed
}
*/
echo "<br />" . "while loop start here" . "<br />" . "<br />";
$b = 15;
while ($b <= 0) // same as for loop you put your condition and it will run until condition become true
{
echo $b . "<br />";
$b -= 1; // here we will pu increment or decrement
}
echo "<br />" . "while loop ends here" . "<br />";
/* ---------- Do While Loop --------- */
/*
** Do While Loop Syntax
do {
// code to be executed
} while (condition);
do...while loop will always execute the block of code once, even if the condition is false.
*/
echo "<br />" . "do while loop start here" . "<br />" . "<br />";
$c = 0;
do { // in do while loop we perform the task first then check condition - in other words if you want to run condition at least one time use this
echo $c . "<br />";
$c++; // increment or decrement
} while ($c < 0); // checking the condition here
echo "<br />" . "do while loop ends here" . "<br />";
/* ---------- Foreach Loop ---------- */
/*
** Foreach Loop Syntax
foreach ($array as $value) {
// code to be executed
}
*/
echo "<br />" . "foreach loop start here" . "<br />" . "<br />";
$posts = ['first post', 'second post', 'third post'];
foreach ($posts as $index => $post) // we use this for array - you can use above loops for arrays as well it just it more common to use - we can get index and individual value from the array using foreach
{
echo "(" . $index . ")" . " " .$post . "<br>";
}
echo "<br />" . "foreach loop ends here" . "<br />";
?>
- php-revision/src/006_functions.php
function- Functions are reusable blocks of code that we can call to perform a specific task. We can pass values into functions to change their behavior. Functions have their own local scope as opposed to global scopenormal functionfunction register_user($email)- to create a function you need to use function key word and then function name and the open brackets - you can use argument in the function - argument can be use to get user input or value which can help function functionalityecho $name . ' registered with ' . $email;// function have strict scope you can't use anything outside or don't use any variable which you declare inside the function outsideglobal $name;// using global keyword we can add global scope variable into local scoperegister_user('makstyle119@gmail.com');// function doesn't run by their own you have to run the manually by calling their name$sum_value = sum(2, 3);// function can run by them self or can be assign to a variable
anonymous function$subtraction = function($a, $b) {// when you assign function directly to a variable like this - this is called anonymous function
arrow function$multiplication = fn($a, $b) => $a * $b;// this is how you can create a arrow function use fn to create a function and if it's a single line function you don't need return or brackets
<?php
/* ------------ Functions ----------- */
/*
Functions are reusable blocks of code that we can call to perform a specific task.
We can pass values into functions to change their behavior. Functions have their own local scope as opposed to global scope
/*
** Function Syntax
function functionName($arg1, $arg2, ...) {
// code to be executed
}
*/
echo "normal function start here" . "<br />" . "<br />";
$name = 'MAK';
function register_user($email) // to create a function you need to use function key word and then function name and the open brackets - you can use argument in the function - argument can be use to get user input or value which can help function functionality
{
global $name; // using global keyword we can add global scope variable into local scope
echo $name . ' registered with ' . $email . "<br />"; // function have strict scope you can't use anything outside or don't use any variable which you declare inside the function outside
}
register_user('makstyle119@gmail.com'); // function doesn't run by their own you have to run the manually by calling their name
function sum($a, $b = 4) {
return $a + $b; // function can return and can be void - your argument can have a default value so you if you don't pass the parameter while calling the function default value will be use
}
$sum_value = sum(2, 3); // function can run by them self or can be assign to a variable
echo $sum_value . "<br />";
echo "<br />" . "normal function ends here" . "<br />";
echo "<br />" . "anonymous function start here" . "<br />";
$subtraction = function($a, $b) // when you assign function directly to a variable like this - this is called anonymous function
{
return $a - $b;
};
echo $subtraction(3, 1) . "<br />";
echo "<br />" . "anonymous function ends here" . "<br />";
echo "<br />" . "arrow function start here" . "<br />";
$multiplication = fn($a, $b) => $a * $b . "<br />"; // this is how you can create a arrow function use fn to create a function and if it's a single line function you don't need return or brackets
echo $multiplication(3, 4) . "<br />";
echo "<br />" . "arrow function ends here" . "<br />";
?>
- php-revision/src/007_array_functions.php
count($fruits);// count array lengthvar_dump(in_array('apple', $fruits));// search in array$fruits[] = 'grape';// add in the lastarray_push($fruits, 'blueberry', 'strawberry');// add in the lastarray_unshift($fruits, 'mango');// add in the firstarray_pop($fruits);// remove lastarray_shift($fruits);// remove firstunset($fruits[2]);// remove by index and also the index$chunked_array= array_chunk($fruits, 2); // second argument is the n$arr3 = array_merge($arr1, $arr2);// merge two arrays$arr4 = [...$arr1, ...$arr2];// merge two arrays$combineColorAndFruitArray = array_combine($color, $fruit);// combine two arrays$keys = array_keys($combineColorAndFruitArray);// return keys of an array$flipped = array_flip($combineColorAndFruitArray);// flip the array$numbersTillTwenty = range(0, 20);// make range in form of array$numbersTillTwentyWithString = array_map(function($number) {return "Number $number";}, $numbersTillTwenty);// run a map in the array$lessThenTen = array_filter($numbersTillTwenty, fn($number) => $number < 10);// run a map and return where condition match$sum = array_reduce($numbersTillTwenty, fn($carry, $number) => $carry + $number);// run a reducer in a array
<?php
/* --------- Array Functions -------- */
/*
Functions to work with arrays
https://www.php.net/manual/en/ref.array.php
*/
// array
$fruits = ['apple', 'orange', 'pear'];
echo "================================================== count start ==================================================" . "<br />" . "<br />";
echo count($fruits); // count array length
echo "<br />" . "<br />" . "================================================== count end ==================================================";
echo "<br />" . "<br />" . "================================================== search start ==================================================" . "<br />" . "<br />";
var_dump(in_array('apple', $fruits)); // search in array
echo "<br />" . "<br />" . "================================================== search end ==================================================";
echo "<br />" . "<br />" . "================================================== add in the array start ==================================================" . "<br />" . "<br />";
$fruits[] = 'grape'; // add in the last
print_r($fruits);
echo "<br />" . "<br />" . "================================================== add in the array end ==================================================";
echo "<br />" . "<br />" . "================================================== array_push start ==================================================" . "<br />" . "<br />";
array_push($fruits, 'blueberry', 'strawberry'); // add in the last
print_r($fruits);
echo "<br />" . "<br />" . "================================================== array_push end ==================================================";
echo "<br />" . "<br />" . "================================================== array_unshift start ==================================================" . "<br />" . "<br />";
array_unshift($fruits, 'mango'); // add in the first
print_r($fruits);
echo "<br />" . "<br />" . "================================================== array_unshift end ==================================================";
echo "<br />" . "<br />" . "================================================== array_pop start ==================================================" . "<br />" . "<br />";
array_pop($fruits); // remove last
print_r($fruits);
echo "<br />" . "<br />" . "================================================== array_pop end ==================================================";
echo "<br />" . "<br />" . "================================================== array_shift start ==================================================" . "<br />" . "<br />";
array_shift($fruits); // remove first
print_r($fruits);
echo "<br />" . "<br />" . "================================================== array_shift end ==================================================";
echo "<br />" . "<br />" . "================================================== unset start ==================================================" . "<br />" . "<br />";
unset($fruits[2]); // remove by index and also the index
print_r($fruits);
echo "<br />" . "<br />" . "================================================== unset end ==================================================";
echo "<br />" . "<br />" . "================================================== split the array into n number - start ==================================================" . "<br />" . "<br />";
$chunked_array = array_chunk($fruits, 2); // second argument is the n
print_r($chunked_array);
echo "<br />" . "<br />" . "================================================== split the array into n number - end ==================================================";
echo "<br />" . "<br />" . "================================================== array merge start ==================================================" . "<br />" . "<br />";
$arr1 = [1, 2, 3];
$arr2 = [4, 5, 6];
$arr3 = array_merge($arr1, $arr2); // merge two arrays
print_r($arr3);
echo "<br />" . "<br />" . "================================================== array merge end ==================================================";
echo "<br />" . "<br />" . "================================================== split operator start ==================================================" . "<br />" . "<br />";
$arr1 = [1, 2, 3];
$arr2 = [4, 5, 6];
$arr4 = [...$arr1, ...$arr2]; // merge two arrays
print_r($arr4);
echo "<br />" . "<br />" . "================================================== split operator end ==================================================";
echo "<br />" . "<br />" . "================================================== combine two array with key value pair - start ==================================================" . "<br />" . "<br />";
$color = ['green', 'red', 'yellow'];
$fruit = ['avocado', 'apple', 'banana'];
$combineColorAndFruitArray = array_combine($color, $fruit); // combine two arrays
print_r($combineColorAndFruitArray);
echo "<br />" . "<br />" . "================================================== combine two array with key value pair - end ==================================================";
echo "<br />" . "<br />" . "================================================== get only keys of an array - start ==================================================" . "<br />" . "<br />";
$keys = array_keys($combineColorAndFruitArray); // return keys of an array
print_r($keys);
echo "<br />" . "<br />" . "================================================== get only keys of an array - end ==================================================";
echo "<br />" . "<br />" . "================================================== flip the array - value become key and key become value - start ==================================================" . "<br />" . "<br />";
$flipped = array_flip($combineColorAndFruitArray); // flip the array
print_r($flipped);
echo "<br />" . "<br />" . "================================================== flip the array - value become key and key become value - end ==================================================";
echo "<br />" . "<br />" . "================================================== create a range from n to m - start ==================================================" . "<br />" . "<br />";
$numbersTillTwenty = range(0, 20); // make range in form of array
print_r($numbersTillTwenty);
echo "<br />" . "<br />" . "================================================== create a range from n to m - end ==================================================";
echo "<br />" . "<br />" . "================================================== create a range with adding more data in return - start ==================================================" . "<br />" . "<br />";
$numbersTillTwentyWithString = array_map(function($number) {
return "Number $number";
}, $numbersTillTwenty); // run a map in the array
print_r($numbersTillTwentyWithString);
echo "<br />" . "<br />" . "================================================== create a range with adding more data in return - end ==================================================";
echo "<br />" . "<br />" . "================================================== filter start ==================================================" . "<br />" . "<br />";
$lessThenTen = array_filter($numbersTillTwenty, fn($number) => $number < 10); // run a map and return where condition match
print_r($lessThenTen);
echo "<br />" . "<br />" . "================================================== filter end ==================================================";
echo "<br />" . "<br />" . "================================================== reduce start ==================================================" . "<br />" . "<br />";
$sum = array_reduce($numbersTillTwenty, fn($carry, $number) => $carry + $number); // run a reducer in a array
var_dump($sum);
echo "<br />" . "<br />" . "================================================== reduce end ==================================================";
?>
- php-revision/src/008_string_functions.php
strlen($string);// Get the length of a stringstrpos($string, 'o');// Find the position of the first occurrence of a substring in a stringstrrpos($string, 'o');// Find the position of the last occurrence of a substring in a stringstrrev($string);// Reverse a stringstrtolower($string);// Convert all characters to lowercasestrtoupper($string);// Convert all characters to uppercaseucwords($string);// Uppercase the first character of each wordstr_replace('World', 'Everyone', $string);// String replacesubstr($string, 0, 5);// Return portion of a string specified by the offset and lengthsubstr($string, 5);// Return portion of a string specified by the offset and lengthstr_starts_with($string, 'Hello')// Starts withstr_ends_with($string, 'Hello')// Starts withhtmlentities($string2);// HTML Entitiesprintf('%s is a %s', 'Brad', 'nice guy');// Formatted Strings - useful when you have outside data - Different specifiers for different data types
<?php
/* ---------- String Functions -------- */
/*
Functions to work with strings
https://www.php.net/manual/en/ref.strings.php
*/
$string = 'Hello World';
// Get the length of a string
echo strlen($string);
// Find the position of the first occurrence of a substring in a string
echo strpos($string, 'o');
// Find the position of the last occurrence of a substring in a string
echo strrpos($string, 'o');
// Reverse a string
echo strrev($string);
// Convert all characters to lowercase
echo strtolower($string);
// Convert all characters to uppercase
echo strtoupper($string);
// Uppercase the first character of each word
echo ucwords($string);
// String replace
echo str_replace('World', 'Everyone', $string);
// Return portion of a string specified by the offset and length
echo substr($string, 0, 5);
echo substr($string, 5);
// Starts with
if (str_starts_with($string, 'Hello')) {
echo 'YES';
}
// Ends with
if (str_ends_with($string, 'ld')) {
echo 'YES';
}
// HTML Entities
$string2 = '<h1>Hello World</h1>';
echo htmlentities($string2);
// Formatted Strings - useful when you have outside data
// Different specifiers for different data types
printf('%s is a %s', 'Brad', 'nice guy');
printf('1 + 1 = %f', 1 + 1); // float
?>
- php-revision/src/009_super_globals.php
$GLOBALS// A superglobal variable that holds information about any variables in global scope.$_GET// Contains information about variables passed through a URL or a form.$_POST// Contains information about variables passed through a form.$_COOKIE// Contains information about variables passed through a cookie.$_SESSION// Contains information about variables passed through a session.$_SERVER// Contains information about the server environment.$_ENV// Contains information about the environment variables.$_FILES// Contains information about files uploaded to the script.$_REQUEST// Contains information about variables passed through the form or URL.
<?php
/* ---------- Superglobals ---------- */
//Built in variables that are always available in all scopes
/*
$GLOBALS - A superglobal variable that holds information about any variables in global scope.
$_GET - Contains information about variables passed through a URL or a form.
$_POST - Contains information about variables passed through a form.
$_COOKIE - Contains information about variables passed through a cookie.
$_SESSION - Contains information about variables passed through a session.
$_SERVER - Contains information about the server environment.
$_ENV - Contains information about the environment variables.
$_FILES - Contains information about files uploaded to the script.
$_REQUEST - Contains information about variables passed through the form or URL.
*/
// var_dump($GLOBALS);
// var_dump($_GET);
// var_dump($_REQUEST);
?>
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
</head>
<body>
<ul>
<li>Host: <?php echo $_SERVER['HTTP_HOST']; ?></li>
<li>Document Root: <?php echo $_SERVER['DOCUMENT_ROOT']; ?></li>
<li>System Root: <?php echo $_SERVER['SystemRoot']; ?></li>
<li>Server Name: <?php echo $_SERVER['SERVER_NAME']; ?></li>
<li>Server Port: <?php echo $_SERVER['SERVER_PORT']; ?></li>
<li>Current File Dir: <?php echo $_SERVER['PHP_SELF']; ?></li>
<li>Request URI: <?php echo $_SERVER['REQUEST_URI']; ?></li>
<li>Server Software: <?php echo $_SERVER['SERVER_SOFTWARE']; ?></li>
<li>Client Info: <?php echo $_SERVER['HTTP_USER_AGENT']; ?></li>
<li>Remote Address: <?php echo $_SERVER['REMOTE_ADDR']; ?></li>
<li>Remote Port: <?php echo $_SERVER['REMOTE_PORT']; ?></li>
</ul>
</body>
</html>
- php-revision/src/010_get_post.php
<?php
/* --- $_GET & $_POST Superglobals -- */
/*
We can pass data through urls and forms using the $_GET and $_POST superglobals.
*/
// echo $_GET['name'] . '<br/>';
// echo $_GET['age'] . '<br/>';
if ($_POST['submit'])
{
echo $_POST['name'] . '<br/>';
echo $_POST['age'] . '<br/>';
}
?>
<a href="<?php echo $_SERVER['PHP_SELF']; ?>?name=MAK&age=22">
Click
</a>
<form action="<?php echo $_SERVER['PHP_SELF']; ?>" method="POST">
<div>
<label for="name">Name: </label>
<input type="text" name="name" />
</div>
<div>
<label for="age">Age: </label>
<input type="text" name="age" />
</div>
<input type="submit" value="submit" name="submit">
</form>
- php-revision/src/011_sanitizing_inputs.php
htmlspecialchars()// Convert special characters to HTML entitiesfilter_var()// Sanitize datafilter_input()// Sanitize inputsFILTER_SANITIZE_STRING// Convert string to string with only alphanumeric, whitespace, and the following characters - _.:/FILTER_SANITIZE_EMAIL// Convert string to a valid email addressFILTER_SANITIZE_URL// Convert string to a valid URLFILTER_SANITIZE_NUMBER_INT// Convert string to an integerFILTER_SANITIZE_NUMBER_FLOAT// Convert string to a floatFILTER_SANITIZE_FULL_SPECIAL_CHARS// HTML-encodes special characters, keeps spaces and most other characters
<?php
/* --- Sanitizing Inputs -- */
/*
Data submitted through a form is not sanitized by default. We have methods to sanitize data manually.
*/
if (isset($_POST['submit'])) {
// $name = $_POST['email'];
// $email = $_POST['email'];
// htmlspecialchars() - Convert special characters to HTML entities
// $name = htmlspecialchars($_POST['name']);
// $email = htmlspecialchars($_POST['email']);
// filter_var() - Sanitize data
// $name = filter_var($_POST['name'], FILTER_SANITIZE_FULL_SPECIAL_CHARS);
// $email = filter_var($_POST['email'], FILTER_SANITIZE_EMAIL);
// filter_input() - Sanitize inputs
$name = filter_input(INPUT_POST, 'name', FILTER_SANITIZE_FULL_SPECIAL_CHARS);
$email = filter_input(INPUT_POST, 'email', FILTER_SANITIZE_EMAIL);
// FILTER_SANITIZE_STRING - Convert string to string with only alphanumeric, whitespace, and the following characters - _.:/
// FILTER_SANITIZE_EMAIL - Convert string to a valid email address
// FILTER_SANITIZE_URL - Convert string to a valid URL
// FILTER_SANITIZE_NUMBER_INT - Convert string to an integer
// FILTER_SANITIZE_NUMBER_FLOAT - Convert string to a float
// FILTER_SANITIZE_FULL_SPECIAL_CHARS - HTML-encodes special characters, keeps spaces and most other characters
} ?>
<!-- Pass data through a form -->
<!-- php_self can be used for xss -->
<form action="<?php echo htmlspecialchars(
$_SERVER['PHP_SELF']
); ?>" method="POST">
<div>
<label>Name: </label>
<input type="text" name="name">
</div>
<br>
<?php echo $email; ?>
<div>
<label>Email: </label>
<input type="email" name="email">
</div>
<br>
<input type="submit" name="submit" value="Submit">
</form>
- php-revision/src/012_cookies.php
$_COOKIE// get cookiesetcookie('name', 'MAK', time() + 86400);// set a cookie - first parameter is name second is value and third is expiry - time() = current time (86400 second are equal to one minute)
<?php
/* ------------- Cookies ------------ */
/*
Cookies are a mechanism for storing data in the remote browser and thus tracking or identifying return users. You can set specific data to be stored in the browser, and then retrieve it when the user visits the site again.
*/
setcookie('name', 'MAK', time() + 86400); // set a cookie - first parameter is name second is value and third is expiry - time() = current time (86400 second are equal to one minute)
if (isset($_COOKIE('name')))
{
echo $_COOKIE('name');
}
setcookie('name', '', time() - 86400)
?>
- php-revision/src/013_sessions.php
$_SESSION// get session$_SESSION['username'] = $username;// set a session - simple assign it to any valueheader('Location: some-page');// redirect to other pagesession_start();// to start a session - must use if you want to use a sessionsession_destroy();// to end a session
<?php
/* ------------ Sessions ------------ */
/*
Sessions are a way to store information (in variables) to be used across multiple pages.
Unlike cookies, sessions are stored on the server.
*/
session_start(); // Must be called before accessing any session data
if (isset($_POST['submit'])) {
$username = filter_input(
INPUT_POST,
'username',
FILTER_SANITIZE_FULL_SPECIAL_CHARS
);
$password = filter_input(
INPUT_POST,
'password',
FILTER_SANITIZE_FULL_SPECIAL_CHARS
);
if ($username == 'brad' && $password == 'password') {
// Set Session variable
$_SESSION['username'] = $username;
// Redirect user to another page
// header('Location: some-page');
} else {
echo 'Incorrect username or password';
}
}
?>
<form action="<?php echo htmlspecialchars(
$_SERVER['PHP_SELF']
); ?>" method="POST">
<div>
<label>Username: </label>
<input type="text" name="username">
</div>
<br>
<div>
<label>Password: </label>
<input type="password" name="password">
</div>
<br>
<input type="submit" name="submit" value="Submit">
</form>
- php-revision/src/014_file_handling.php
file_exists// if file existfopen// open a file - required file path and permission - 'r' Read | 'w' Writefread// read a file;fclose// close a filefwrite// write a file
<?php
/* ---------- File Handling --------- */
/*
File handling is the ability to read and write files on the server.
PHP has built in functions for reading and writing files.
*/
$file = 'some_path/users.txt';
if (file_exists($file))
{
// echo readfile($file);
$handle = fopen($file, 'r');
$contents = fread($handle, filesize($file));
fclose($handle);
echo $contents;
} else {
$handle = fopen($file, 'w');
$contents = 'MAK' . PHP_EOL . 'MARIA' . PHP_EOL . 'ALI';
fwrite($handle, $contents);
fclose($handle);
}
?>
- php-revision/src/015_file_upload.php
$_FILES// get a file$_FILES['upload']['name']// file name$_FILES['upload']['size']// file size$_FILES['upload']['tmp_name']// file tmp_namemove_uploaded_file// upload a file in the folder structure
<?php
/* ----------- File upload ---------- */
$allowed_ext = array('png', 'jpg', 'jpeg', 'gif');
if(isset($_POST['submit'])) {
// Check if file was uploaded
if(!empty($_FILES['upload']['name'])) {
$file_name = $_FILES['upload']['name'];
$file_size = $_FILES['upload']['size'];
$file_tmp = $_FILES['upload']['tmp_name'];
$target_dir = "uploads/$file_name";
// Get file extension
$file_ext = explode('.', $file_name);
$file_ext = strtolower(end($file_ext));
// echo $file_ext;
// Validate file type/extension
if(in_array($file_ext, $allowed_ext)) {
// Validate file size
if($file_size <= 1000000) { // 1000000 bytes = 1MB
// Upload file
move_uploaded_file($file_tmp, $target_dir);
// Success message
echo '<p style="color: green;">File uploaded!</p>';
} else {
echo '<p style="color: red;">File too large!</p>';
}
} else {
$message = '<p style="color: red;">Invalid file type!</p>';
}
} else {
$message = '<p style="color: red;">Please choose a file</p>';
}
}
?>
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>File Upload</title>
</head>
<body>
<?php echo $message ?? null; ?>
<form action="<?php echo htmlspecialchars(
$_SERVER['PHP_SELF']
); ?>" method="post" enctype="multipart/form-data">
Select image to upload:
<input type="file" name="upload">
<input type="submit" value="Submit" name="submit">
</form>
</body>
</html>
- php-revision/src/016_exception.php
throw new Exception// add a new errortry// we will try things here - code which we want to runcatch (Exception $e)// only if code break it will get herefinally// always run no matter what you do in try or catch - optional
<?php
/* ----------- Exceptions ----------- */
/*
PHP has an exception model similar to that of other programming languages. An exception can be thrown, and caught ("catched") within PHP. Code may be surrounded in a try block, to facilitate the catching of potential exceptions. Each try must have at least one corresponding catch or finally block.
*/
function inverse($x)
{
if (!$x)
{
throw new Exception('Division by zero');
}
return 1/$x;
}
try {
echo inverse(5);
echo inverse(0);
} catch (Exception $e) {
echo 'Catch Exception' . $e->getMessage(). ' ';
} finally {
echo 'first finally';
}
echo 'hello world';
?>
- php-revision/src/017_oop.php
class// class are like object we can create them to use them multiple timesAccess Modifiers// public, private, protectedpublic// can be accessed from anywhereprivate// can only be accessed from inside the classprotected// can only be accessed from inside the class and by inheriting classesextends// you can Inherit any class using extends keyword and you can now use protected and public method hereparent::// access any parent method
<?php
/* --- Object Oriented Programming -- */
/*
From PHP5 onwards you can write PHP in either a procedural or object oriented way. OOP consists of classes that can hold "properties" and "methods". Objects can be created from classes.
*/
class User {
// Properties are just variables that belong to a class.
// Access Modifiers: public, private, protected
// public - can be accessed from anywhere
// private - can only be accessed from inside the class
// protected - can only be accessed from inside the class and by inheriting classes
private $name;
public $email;
public $password;
// The constructor is called whenever an object is created from the class.
// We pass in properties to the constructor from the outside.
public function __construct($name, $email, $password) {
// We assign the properties passed in from the outside to the properties we created inside the class.
$this->name = $name;
$this->email = $email;
$this->password = $password;
}
// Methods are functions that belong to a class.
public function set_name($name) {
$this->name = $name;
}
function get_name() {
return $this->name;
}
}
$user1 = new User('Moiz', 'moiz@test.com', 'some-password');
$user2 = new User('Maria', 'moiz@test.com', 'some-password');
// $user1->name = 'MAK'; // you can't access a protected property
$user2->set_name('MAK');
var_dump($user1);
echo $user2->get_name();
// Inheritance
class employee extends User {
private $title;
public function __construct($name, $email, $password, $title)
{
parent::__construct($name, $email, $password);
$this->title = $title;
}
public function get_title()
{
return $this->title;
}
}
$employ1 = new employee('moiz ali', 'moiz.ali@test.com', 'someCoolPassword123!', 'Software Engineer');
// var_dump($employ1);
echo $employ1->get_title();
includes// use to include a file - no error if file not foundrequire// use to include a file - error if file not foundrequire_one// use to include a file - if already include then doesn't include twice
<= less than>= greater than<== less than or equal to>== greater than or equal to=== equal to==== identical to!= not comparison!== mot equal to!=== not identical to?= (in ternary operator) if:= (in ternary operator) else??= or comparison&&= and comparison||= or comparison
//this is a single line comment = use for single line comments/* this is a multi-line comment */= use for multi line commentskabab caseis recommended inPHP, eg: my_app.PHPignorewhite spacesso you can hit the enter button as much as you want - ( not recommended )incuse for component folder
I start my journey using this cool stuff so shout to them: