PHP
- Getting started with PHP
- Awesome Book
- Awesome Community
- Awesome Course
- Awesome Tutorial
- Awesome YouTube
- Alternative Syntax for Control Structures
- APCu
- Array iteration
- Arrays
- Asynchronous programming
- Autoloading Primer
- BC Math (Binary Calculator)
- Cache
- Classes and Objects
- Closure
- Coding Conventions
- Command Line Interface (CLI)
- Comments
- Common Errors
- Compilation of Errors and Warnings
- Compile PHP Extensions
- Composer Dependency Manager
- Constants
- Contributing to the PHP Core
- Contributing to the PHP Manual
- Control Structures
- Cookies
- Create PDF files in PHP
- Cryptography
- Datetime Class
- Debugging
- Dependency Injection
- Design Patterns
- Docker deployment
- Exception Handling and Error Reporting
- Executing Upon an Array
- File handling
- Filters & Filter Functions
- Functional Programming
- Functions
- Generators
- Headers Manipulation
- How to break down an URL
- How to Detect Client IP Address
- HTTP Authentication
- Image Processing with GD
- Imagick
- IMAP
- Installing a PHP environment on Windows
- Installing on Linux/Unix Environments
- JSON
- Localization
- Loops
- Machine learning
- Magic Constants
- Magic Methods
- Manipulating an Array
- mongo-php
- Multi Threading Extension
- Multiprocessing
- Namespaces
- Object Serialization
- Operators
- Output Buffering
- Outputting the Value of a Variable
- Parsing HTML
- Password Hashing Functions
- PDO
- Performance
- PHP Built in server
- PHP MySQLi
- php mysqli affected rows returns 0 when it should return a positive integer
- PHPDoc
- Processing Multiple Arrays Together
- PSR
- Reading Request Data
- Recipes
- References
- Reflection
- Regular Expressions (regexp/PCRE)
- Secure Remeber Me
- Security
- Sending Email
- Serialization
- Sessions
- SimpleXML
- SOAP Client
- SOAP Server
- Sockets
- SPL data structures
- SQLite3
- Streams
- String formatting
- String Parsing
- Superglobal Variables PHP
- Traits
- Type hinting
- Type juggling and Non-Strict Comparison Issues
- Types
- Unicode Support in PHP
- Unit Testing
- URLs
- Using cURL in PHP
- Using MongoDB
- Using Redis with PHP
- Using SQLSRV
- UTF-8
- Variable Scope
- Variables
- WebSockets
- Working with Dates and Time
- XML
- YAML in PHP
PHP Constants
Syntax
- define ( string $name , mixed $value [, bool $case_insensitive = false ] )
- const CONSTANT_NAME = VALUE;
Remarks
Constants are used to store the values that are not supposed to be changed later. They also are often used to store the configuration parameters especially those which define the environment (dev/production).
Constants have types like variables but not all types can be used to initialize a constant. Objects and resources cannot be used as values for constants at all. Arrays can be used as constants starting from PHP 5.6
Some constant names are reserved by PHP. These include true, false, null as well as many module-specific constants.
Constants are usually named using uppercase letters.
