PHP tips and tricks

Contents:

• Duplicate Type
• Yield Or Return
• Multiple Method In Interface
• Operator Overloading
• Three Return Errors
• array_unique() Is Slow
• Cloning Static Variable
• Datetime And Leap Second
• Silent Type Cast
• Objects As Keys In Foreach
• isset() On Uninitialized Properties
• Recycle Generator
• Of Integers And Floats
• max() On Strings
• e And Euler
• Closure On Constructor
• ++ Riddle
• Oversigned Integers
• Local Variable Cost
• Array Items By Value
• Not Set But Exists
• Sorting Enum
• Hypotenuse In Action
• Spaceship Always False
• Inverted Spaceship Results
• isset(), empty() And the Magic Methods
• Comparing Arrays And Object
• Mixed Compatibility
• Where Did The Comma Go?
• Argument Renaming
• When htmlemtities() Is Failing
• Static Arrow Function
• defined() In Action
• expm1() And log1p()
• Is A Class Constant Set?
• preg_split() Magic
• Comparing NAN
• array_unique() And Enum
• Display A Tree Natively
• Speed Up CSV Write To Disk
• php://memory And Maxmemory
• ::parent Operator
• Stuttering PHP
• Riddle: $this<-code
• Multiple Const Types
• Replacing PHP http Wrapper
• Cast But Not A Cast
• Hexadecimal Separator
• Call echo With Commas
• Reusing Decimals For Bananas
• Where To Put The Cast?
• Unpacking A Single Element Array
• Abstract Or Not
• (int) And (ant)
• Cast In Const
• global Overwrites
• Property Hooks And Default Values
• Static And Not Static Method
• intval() And Its Arguments
• Easy Map
• Returning Void
• Casting An Enum Case
• Dynamic Class Constant Edge Cases
• Dynamic Enum Cases
• Yield And Keys
• Array Callback Index
• Time Of Closure Creation
• Coalesce And The Fatal Error
• Weakmap And Enums
• parent In Function
• isset() And The Fatal Error
• All PHP Dereferencements
• No Property Beyond Limits
• Can’t Be Compatible With Less Arguments
• Arrow Functions Import Variables By Values
• Never Is The Lowest Ranking Type
• The Never Function Arrow
• No Rewrite For Exit
• Alias Conflicts
• Not All Incremented Strings Are Deprecated
• get_class() Or ::class?
• No Binding But With Original
• Infinite foreach()
• Who Modifies This Property?
• mixed Is Not No Type
• The Recursive array_merge()
• $GLOBALS Is Not Defined
• Cast Private To Array
• Properties In Interfaces
• Bitwise Operations On String
• Typed Variables
• Type And Reference
• Chaining Spaceship
• parse_str() Edge Cases
• Cast A Closure To Array
• list() Does Not Type
• Triple Plus Operator
• Function Name In A Method
• PHP Quine
• Named Parameter In An Array
• self Is A Valid Type On A Closure
• Keep Interface New Argument Compatible
• Undefined Constant A On Its Line Of Definition
• http_build_query() And Enumerations
• Cannot indirectly modify readonly
• Ellipsis And Coalesce
• namespace namespace
• Namespace, But Far In The Name
• No Hidden Nullable
• Remove Last Item In An Array
• Cancelling Native Function
• Classes Constant Disambiguation With Parenthesis
• compact() Is Recursive
• No Final Parameter
• Is Not A NAN
• Impossible Named Arguments
• func_get_args() Skips Variadic
• Ellipsis With Array Parameters
• Named Parameter Inheritance
• __invoke() On New
• Method Or Property?
• No More Class _
• Method Not Property Name Must Be String
• Static Properties
• The New And The Parenthesis
• Fluent Function
• Cannot Use Isset On Expression, So Use What?
• Constant Redefinition
• No Class Constant In String
• Return Int Not Bool
• By Reference, Error Or Notice?
• Call Function With Strings
• Non Empty Match
• Named Sqlite3 In Memory
• Variable Creation
• All Enum Cases
• Unicode Comments
• Datetime Object, And Years
• Escaping A Regex
• Every Anonymous Class Is Different
• instanceof With Variables
• Undefined Variable
• Compatible Signature
• private Is Relaxed
• Class Implement No More
• Variadic Are Typed And Defaulted
• array_column() To Hash
• \array Was Customizable
• array Is Not An Array
• array_map_assoc() With Keys
• array_map() Goes Full Throttle
• Typed Array
• Initialize Readonly On Child
• Silent Optimisation Of Variables
• Modify String With Array Syntax
• No Force Object To String
• __invoke() Method And Properties
• Constructor Needed
• No Self Referencing Constants
• Deanonymize Class
• Noscream On Ellipsis
• Incompatible Promoted Readonly
• Where Is The Semicolon?
• Self As Attribute
• Reading Micro-seconds
• Promoted Properties Compatibility
• Enum Are Not Linted
• Sorting With Minus
• Override With Interface
• Send An Argument To Generator
• PHP Integer Format
• Compatible Only Interface
• No Cast In Constant Expressions
• Lots Of Silly Arguments
• Child Of Attribute Is Not An Attribute
• Dynamic Class Constant
• The Function Method
• Match() With Multiple Values
• Interfaces Constants Conflicts
• Foreach() Skips Uninitialized Properties
• Casting And Power
• Attribute Without Class
• Class Is A Valid Type
• Float Precision
• Store Float As Index
• Case Insensitive Cast
• $this $this
• No Returntype But Still, Only String
• No Unknown For array_merge()
• No Returntype Enforced
• As As As
• No DNF For Catch
• new On Object
• Unfinished Class Doesn’t Compile
• Yield, Not Return By Reference
• class_exists() With Enums
• No Semicolon In Sight
• glob() With Hidden Files
• A Function Called file_append_contents()
• array_reduce() To Filter And Alter
• $this Is Not Of The Current Class
• Class Constants With Different Types
• No Change To $this
• file_put_contents() With Array Argument
• Get The Generator
• Redefine Native Functions
• A Static Method Cannot Call A Non Static Method
• Declared Before Or After
• Cast Is So Strong
• Roman Loops
• Finally Catches Exception
• Abstract Again
• Always Compatible Variadic
• Yield, Not Return
• try, catch, finally Are All Optional
• null Or Boolean As Array
• Hide Sensitive Parameter
• No Property In Interface
• The Uncallable Function
• Easy Wither Call
• Array Is Full
• Const Without Parenthesis
• Cast Are Case Insensitive
• Array And Object Syntax, Not The Same Error
• When Space Matters
• array array = array()
• Cannot Yield And Never
• Class Invasion Both Ways
• Typed By Enum
• Change A Static Variable Outside Its Function
• Scalar Types Are Unqualified
• array_append() And Short Assignation
• Coalesce And Null
• All Classes Aliases
• Mixed And Untyped Are Not Compatible Types
• Abstract Constants
• Cannot Static Static Property
• More Attribute Usage
• Run Any Script In A Phar
• Static Variable Outside A Method
• Enumeration’s Cases Comparisons
• All Static Curly Syntaxes And One Wrong
• No Such Function As Empty
• Strange –> Operator
• Unexpected Keys In Array
• Recursive Generator
• Documenting Parameters
• Catch Is Optional
• Void Parameter In array_keys()
• Unsetting Properties Surprises
• Multiple Aliases
• Plus Plus Minus Minus
• Constants Can Be Impossible
• Constants Are Mutable
• Quick DTO Or VO Copy
• Stealth Generator
• Quick Serialize
• Clone Clone Clone
• Set readonly Properties Outside The Class
• Exception Polymorphism
• Exponential Minus One
• PHP Infinity Is Reachable
• Negative Squares
• Negating An Assignation
• Numeric Separators Inside A String?
• Identifier Confusions
• Relaxed Syntax With Const
• Closure To Call
• Get $this In A Static
• How To array_intersect_uassoc_insensitive()
• Class And Constant Confusion
• Don’t Forget To Yield
• Inconsistent Constructor Signatures
• foreach() With All The Same Keys
• Battle Of Definition
• Variadic All The Yields
• Refactoring strpos()
• is_a() Versus Instanceof
• Exporting Properties
• Another Cast To Int
• ReturnTypeWillChange Is For All
• URL As Comments
• Coalesce And Assignation
• Missing Methods Are Fatal
• Only Initialize With Short Assignation Coalesce
• Keys Are Integers Whenever Possible
• Fast Creation Of stdClass Objects
• An Elephpant In The Code
• Internal Static Call
• strict_types Exceptions
• Playing With Integers Limits
• Signature Compatibility Exception
• Object Is Not A Type
• Forgotten Throw
• Keywords In Namespaces
• No Warning For Unused Variables
• Self In An Interface
• instanceof Object
• stdClass Object
• A Case Of Misplaced Parenthesis
• Checking For Names At Different Times
• Integer Becomes Negative
• Not All Strings In Arrays
• Recursive Arrow Function
• null Does Not Always Equal false
• Recursive Closure
• Cast Precedence
• Enum As A Name
• Type Is Not Always Returned
• The Namespace Stack
• Catch On Interfaces