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
- Anonymous function
- Assignment to variables
- Closures
- Common functional methods in PHP
- Objects as a function
- Passing a callback function as a parameter
- Pure functions
- Scope
- Using built-in functions as callbacks
- Using outside variables
- 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
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- Machine learning
- Magic Constants
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- 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 Functional Programming Using built-in functions as callbacks
Example
In functions taking callable as an argument, you can also put a string with PHP built-in function. It's common to use trim as array_map parameter to remove leading and trailing whitespace from all strings in the array.
$arr = [' one ', 'two ', ' three'];
var_dump(array_map('trim', $arr));
// array(3) {
// [0] =>
// string(3) "one"
// [1] =>
// string(3) "two"
// [2] =>
// string(5) "three"
// }
