PHP Install
Check PHP version
Install explained
PHP Syntax
Write text to the output using PHP Keywords, classes, functions, and user-defined functions ARE NOT case-sensitive Variable names ARE case-sensitive
Syntax explained
PHP Comments
Single-line comment before code line Single-line comment at the end of code line Use comment to prevent code from being executed Multi-line comment Multi-line comment to ignore code
Comments explained
PHP Variables
Create variables Output some text and the value of a variable Output the sum of two variables Assign the same value to multiple variables in one line Use var_dump() to return the data type of variables Global scope (variable outside function) Local scope (variable inside function) Static scope (let a local variable not be deleted after execution of function) Use the global keyword to access a global variable from within a function Use the $GLOBALS[] array to access a global variable from within a function
Variables explained
PHP Echo and Print
Echo - Output text Echo - Output variables Echo - Single or double quotes? Print - Output text Print - Output variables Print - Single or double quotes?
Echo and Print explained
PHP Data Types
PHP string PHP integer PHP float PHP boolean PHP array PHP object PHP NULL
Data Types explained
PHP Strings
strlen() - Return the length of a string str_word_count() - Count the number of words in a string str_contains() - Check if a string contains a specific substring strpos() - Search for a specific text within a string strtoupper() - Returns a string in upper case strtolower() - Returns a string in lower case str_replace() - Replaces some characters with some other characters in a string strrev() - Reverse a string trim() - Removes any whitespace from the beginning/end of a string explode() - Splits a string into an array substr() - Extract a part of a string (slice a string) Use escape character
Strings explained
PHP Numbers
is_int() - Check if variable is of type integer is_float() - Check if variable is of type float is_infinite() - Check if a numeric value is infinite is_nan() - Check if a value is "Not A Number" (NAN) is_numeric() - Check if a variable is a number or a numeric string is_numeric() - Check if a variable is a number or a numeric string intval() - Return the integer value of a variable
Numbers explained
PHP Casting
Cast to String Cast to Integer Cast to Float Cast to Boolean Cast to Array Cast to Object Cast to NULL
Casting explained
PHP Math
pi() - Return value of PI min(), max() - Find the lowest and highest value in a list of arguments abs() - Return the absolute (positive) value of a number sqrt() - Return the square root of a number round() - Round a floating-point number to its nearest integer rand() - Generate a random number rand() - Generate a random number between 10 and 100
Math explained
PHP Constants
define() - Create a constant Declare a constant inside a function, and output it outside the function const keyword - Create a constant Create Array constants with define() or const
Constants explained
PHP Magic Constants
The CLASS constant The DIR constant The FILE constant The FUNCTION constant The FUNCTION constant The METHOD constant The NAMESPACE constant The TRAIT constant The ClassName::class constant
Magic Constants explained
PHP Operators
Arithmetic operator: Addition (+) Arithmetic operator: Subtraction (-) Arithmetic operator: Multiplication () Arithmetic operator: Division (/) Arithmetic operator: Modulus (%) Arithmetic operator: Exponentiation () Assignment operator: x = y Assignment operator: x += y Assignment operator: x -= y Assignment operator: x = y Assignment operator: x /= y Assignment operator: x %= y Comparison operator: Equal (==) Comparison operator: Identical (===) Comparison operator: Not equal (!=) Comparison operator: Not equal (< > ) Comparison operator: Not identical (!==) Comparison operator: Greater than ( > ) Comparison operator: Less than (<) Comparison operator: Greater than or equal ( > =) Comparison operator: Less than or equal (<=) Comparison operator: Spaceship (<= > ) Increment operator: ++$x Increment operator: $x++ Decrement operator: --$x Decrement operator: $x-- Logical operator: and Logical operator: or Logical operator: xor Logical operator: && (and) Logical operator: || (or) Logical operator: not String operator: Concatenation of $txt1 and $txt2 String operator: Appends $txt2 to $txt1 Array operator: Union (+) Array operator: Equality (==) Array operator: Identity (===) Array operator: Inequality (!=) Array operator: Inequality (< > ) Array operator: Non-identity (!==) Conditional assignment operator: Ternary (?:) Conditional assignment: Null coalescing (??)
Operators explained
PHP If Statements
The if statement executes some code only if the specified condition is true The if...else statement executes some code if a condition is true, and another code if condition is false The if...elseif...else statement executes different codes for more than two conditions Shorthand if Shorthand if...else Nested if
If Statements explained
PHP Switch Statement
The switch statement performs different actions based on different conditions The default keyword specifies the code to run if there is no case match Combining cases
Switch Statement explained
PHP Match Expression
The match expression performs different actions based on different conditions Match multiple values for the same code block
Match Expression explained
PHP Loops
while loop - Loops through a block of code as long as the specified condition is true do...while loop - Loops through a block of code at least once, and then repeats the loop as long as the specified condition is true Another do...while loop for loop - Loops through a block of code a specified number of times foreach loop - Loops through a block of code for each element in an array or each property in an object
Loops explained
PHP Functions
Create and call a function Function with one parameter Function with two parameters Function with default parameter value Function with return value Passing arguments by reference Variable number of parameters
Functions explained
PHP Arrays
Create and display an indexed array Access a specific array item with index number Change value of array item Loop through an indexed array Create and display an associative array Access a specific array item with key name Change value of array item Loop through an associative array Add more array items to the end of an indexed array Add more array items to the end of an associative array array_push() - Add one or more array items to the end of an array array_unshift() - Add one or more array items to the beginning of an array array_splice() - Remove a portion of an array and replace it with new items array_merge() - Merge two or more arrays array_pop() - Remove the last item of an array array_shift() - Remove the first item of an array sort() - Sorts an indexed array in ascending order rsort() - Sorts an indexed array in descending order asort() - Sorts an associative array in ascending order (value) arsort() - Sorts an associative array in descending order (value) ksort() - Sorts an associative array in ascending order (key) krsort() - Sorts an associative array in descending order (key) Create a multidimensional array Loop through a multidimensional array (for loop) Loop through a multidimensional array (foreach loop)
Arrays explained
PHP Superglobals
$GLOBAL - Used to access global variables from anywhere in the script $_SERVER - Holds information about headers, paths, and script locations $_REQUEST - Contains data from submitted forms, URL query strings, and HTTP cookies $_POST - Contains an array of variables received via the HTTP POST method $_GET - Contains an array of variables received via the HTTP GET method
Superglobals explained
PHP Regular Expressions
Regex Modifier: i Regex Modifier: m Regex Modifier: [abc] Regex Modifier: [^abc] Regex Modifier: [a-z] Regex Modifier: [A-z] Regex Modifier: [A-Z] Regex Modifier: [123] Regex Modifier: [0-5] Regex Modifier: [0-9] Regex Modifier: | Regex Modifier: . Regex Modifier: ^ Regex Modifier: $ Regex Modifier: \d Regex Modifier: \D Regex Modifier: \s Regex Modifier: \S Regex Modifier: \w Regex Modifier: \W Regex Modifier: \b Regex Modifier: \u Regex Modifier: n+ Regex Modifier: n{3} Regex Modifier: n{2, 5} Regex Modifier: n{3,}
Regular Expressions explained
PHP Regular Expression Functions
preg_match() - Returns 1 if the pattern was found in the string, otherwise 0 preg_match_all() - Returns how many matches were found for a pattern in a string preg_replace() - Replaces all matches of the pattern in a string with another string preg_split() - Splits a string into an array using matches of a regular expression as separators preg_grep() - Returns an array containing only elements from the input that match the given pattern
Regular Exp Functions explained
PHP Form Validation
PHP Form Validation
Form Validation explained
PHP Date and Time
date() Format today's date in several ways Automatically update the copyright year Output the current time (server time) Set timezone, then output current time Return default timezone mktime() - Create a date and time from a number of parameters Format a timestamp to a readable date and time strtotime() - Convert strings to dates Output the dates for the next six Saturdays
Date and Time explained
PHP Include Files
Use include to include "footer.php" in a page Use include to include "menu.php" in a page Use include to include "vars.php" in a page Use include to include a non-existing file Use require to include a non-existing file
Include Files explained
PHP File Handling
readfile() - Read a file and write it to the output buffer
File Handling explained
PHP File Open/Read/Close
Use fopen(), fread(), and fclose() to open, read, and close a file Use fgets() to read a single line from a file Use feof() to read through a file, line by line, until end-of-file is reached Use fgetc() to read a single character from a file
File Open/Read/Close explained
PHP Sessions
Start a new session, and set session variables Get session variable values Get all session variable values Modify a session variable Destroy a session
Sessions explained
PHP Filters
filter_list() - List all supported filter names and ids Sanitize and validate an email Sanitize and validate a URL Validate an integer Validate an integer that is 0 Validate an IP address Validate an integer within a range Validate IPv6 address Validate URL - Must contain querystring Sanitize string - Remove characters with ASCII value > 127
Filters explained
PHP Callback Functions
Use a named function as a callback Use an anonymous function as a callback Callbacks in user defined functions
Callback Functions explained
PHP and JSON
Encode an associative array into a JSON object Encode an indexed array into a JSON object Decode JSON data into a PHP object Decode JSON data into an associative array Access the values from a PHP object Access the values from an associative array Loop through the values of a PHP object Loop through the values of an associative array
PHP and JSON explained
PHP Exceptions
Throw an exception without catching it Display a message when an exception is thrown, and continue script Display a message when an exception is thrown, and then indicate that the process is complete Output information about an exception that was thrown
PHP Exceptions explained
PHP Object-Oriented Programming (OOP)
Create a class and two objects The instanceof keyword checks if an object belongs to a specific class __construct() - Create a constructor __destruct() - Create a destructor Access modifier: Public Access modifier: Private Access modifier: Protected Inheritance A constant can be accessed fom outside the class A constant can be accessed fom inside the class Abstract class Abstract method with argument Define and use an Interface Use an Interface 2 Define and use a Trait Use multiple Traits Declare a Static method Declare a Static property
PHP OOP explained
PHP MySQL Database
Select data with MySQLi (Object-oriented) Select data with MySQLi (Procedural) Put result in an HTML table (MySQLi Object-oriented) Select and filter data with MySQLi (Object-oriented) Select and filter data with MySQLi (Procedural) Select and order by with MySQLi (Object-oriented) Select and order by with MySQLi (Procedural)
MySQL Database explained
PHP SimpleXML Parser
simplexml_load_string() - Read XML data from a string simplexml_load_file() - Read XML data from a file Get node values Get node values of specific elements Get node values - loop Get attribute values Get attribute values - loop
SimpleXML Parser explained
PHP XML Expat Parser
Initialize an XML Expat parser, define some handlers, then parse an XML file
XML Expat Parser explained
PHP and AJAX
AJAX and PHP AJAX and MySQL
AJAX explained