PHP Cheat Sheet

PHP is a popular server-side scripting language that is used to create dynamic web pages. It was first developed in 1994 by Rasmus Lerdorf and has since become one of the most widely used programming languages on the web. PHP is an open-source language, which means that it is free to use and can be modified by anyone.

One of the main advantages of PHP is its versatility. It can be used to create a wide range of web applications, from simple blogs to complex e-commerce sites. PHP is also compatible with a variety of databases, including MySQL, Oracle, and PostgreSQL, making it a popular choice for web developers.

Another advantage of PHP is its ease of use. The language is relatively simple to learn, even for beginners, and there are many resources available online to help developers get started. PHP also has a large community of developers who contribute to its development and provide support to others.

One of the key features of PHP is its ability to interact with HTML and other web technologies. This allows developers to create dynamic web pages that can respond to user input and display data from databases. PHP also supports a wide range of programming paradigms, including object-oriented programming, procedural programming, and functional programming.

In conclusion, PHP is a powerful and versatile programming language that is widely used in web development. Its ease of use, compatibility with databases, and ability to interact with other web technologies make it a popular choice for developers. Whether you are a beginner or an experienced developer, PHP is a language that is worth learning.

Cheat Sheet

This cheat sheet provides a quick reference guide for PHP developers. It is divided into different sections based on the theme.

Variables

Syntax	Description
$variable_name = value;	Assigns a value to a variable
$variable_name++;	Increments the value of a variable by 1
$variable_name--;	Decrements the value of a variable by 1
$variable_name += value;	Adds a value to the variable
$variable_name -= value;	Subtracts a value from the variable
$variable_name *= value;	Multiplies the variable by a value
$variable_name /= value;	Divides the variable by a value
$variable_name %= value;	Modulus the variable by a value

Data Types

Syntax	Description
string	A sequence of characters
integer	A whole number
float	A number with a decimal point
boolean	A value that is either true or false
array	A collection of values
object	An instance of a class
null	A variable with no value

Operators

Syntax	Description
+	Addition
-	Subtraction
*	Multiplication
/	Division
%	Modulus
.	Concatenation
==	Equal to
!=	Not equal to
>	Greater than
<	Less than
>=	Greater than or equal to
<=	Less than or equal to
&&	Logical AND
||	Logical OR
!	Logical NOT

Control Structures

If Statement

if (condition) {
    // code to execute if condition is true
} else {
    // code to execute if condition is false
}

Switch Statement

switch (variable) {
    case value1:
        // code to execute if variable equals value1
        break;
    case value2:
        // code to execute if variable equals value2
        break;
    default:
        // code to execute if variable does not equal any of the values
        break;
}

For Loop

for (initialization; condition; increment) {
    // code to execute repeatedly
}

While Loop

while (condition) {
    // code to execute repeatedly while condition is true
}

Do-While Loop

do {
    // code to execute at least once
} while (condition);

Functions

function function_name(parameter1, parameter2, ...) {
    // code to execute
    return value;
}

Arrays

Indexed Array

$my_array = array(value1, value2, value3, ...);

Associative Array

$my_array = array(key1 => value1, key2 => value2, key3 => value3, ...);

Multidimensional Array

$my_array = array(
    array(value1, value2, value3, ...),
    array(value4, value5, value6, ...),
    ...
);

Classes and Objects

Class Definition

class class_name {
    // properties and methods
}

Object Creation

$object_name = new class_name();

Property Access

$object_name->property_name;

Method Call

$object_name->method_name(parameter1, parameter2, ...);

File Handling

Opening a File

$file_handle = fopen(""file_name"", ""mode"");

Reading from a File

$file_contents = fread($file_handle, file_size);

Writing to a File

fwrite($file_handle, $data);

Closing a File

fclose($file_handle);

Database Connectivity

Connecting to a Database

$connection = mysqli_connect(host, username, password, database_name);

Querying a Database

$result = mysqli_query($connection, query);

Fetching Data from a Query Result

$row = mysqli_fetch_array($result);

Closing a Database Connection

mysqli_close($connection);

Error Handling

Displaying Errors

ini_set('display_errors', 1);
error_reporting(E_ALL);

Handling Errors

try {
    // code that may throw an exception
} catch (Exception $e) {
    // code to handle the exception
}