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The Serializable interface in PHP allows custom classes to define their own serialization behavior. While PHP's built-in serialize() function can handle most data types, objects of user-defined classes need this interface to control how they are converted to and from string representations. Syntax Serializable { /* Methods */ abstract public serialize() : string abstract public unserialize(string $serialized) : void } Methods Serializable::serialize() − Returns a string representation of the object Serializable::unserialize() − Reconstructs the object from its serialized string representation ... Read More
The Iterator interface extends the abstract Traversable interface in PHP. It allows user-defined classes to become iterable using foreach loops. PHP provides many built-in iterators (called SPL iterators) like ArrayIterator, DirectoryIterator, etc. A user class implementing the Iterator interface must implement all its abstract methods. Syntax Iterator extends Traversable { /* Methods */ abstract public current ( void ) : mixed abstract public key ( void ) : scalar abstract public next ( void ) : void abstract public rewind ( void ... Read More
In PHP, the ArrayAccess interface allows objects to be accessed like arrays using square bracket notation. When a class implements this interface, you can use $obj['key'] syntax to interact with the object's internal data without exposing the underlying array property directly. Syntax ArrayAccess { /* Methods */ abstract public offsetExists ( mixed $offset ) : bool abstract public offsetGet ( mixed $offset ) : mixed abstract public offsetSet ( mixed $offset , mixed $value ) : void ... Read More
PHP throws ArgumentCountError when a function or method is called with fewer arguments than required in its definition. The ArgumentCountError class inherits from TypeError and can be caught using try-catch blocks. Basic Function Example Here's an example where a user-defined function add() expects two arguments but receives only one ? Too few arguments to function add(), 1 passed and exactly 2 expected Class Method Example ArgumentCountError also occurs with class methods when insufficient arguments are provided ? Too few arguments to function MyClass::setData(), ... Read More
The ArithmeticError class is inherited from the Error class. This type of error occurs while performing certain mathematical operations. One such scenario is attempting to perform a bitwise shift operation by a negative amount. This error is also thrown when a call to the intdiv() function results in a value that is beyond the legitimate boundaries of an integer. Bitwise Shift with Negative Number In the following example, an attempt is made to use the binary shift operator with a negative operand. This results in an ArithmeticError ? Bit shift by negative ... Read More
The AssertionError class is a subclass of the Error class in PHP. This exception is thrown when the assert() function evaluates to FALSE. The assert() function checks if a given assertion is true and throws an AssertionError if the condition fails. Syntax // PHP 5 and PHP 7 assert ( mixed $assertion [, string $description ] ) : bool // PHP 7 only assert ( mixed $assertion [, Throwable $exception ] ) : bool Parameters Parameter Description assertion String or boolean expression to evaluate description Failure message ... Read More
In PHP 7.3 onwards, CompileError exception has been added. This class inherits the Error class. Some error conditions that previously resulted in fatal errors now throw a CompileError. This affects compilation errors that are likely to be thrown by the token_get_all() function when parsing invalid PHP syntax. The token_get_all() function uses Zend lexical scanner to parse a given string into PHP language tokens. When used in TOKEN_PARSE mode, it can throw a CompileError for invalid PHP code. Syntax token_get_all ( string $source [, int $flags = 0 ] ) : array Parameters ... Read More
The DivisionByZeroError class is a subclass of ArithmeticError class. This type of error occurs when division operations involve a denominator value of zero. This can also occur when a modulo operator (%) has 0 as the second operand, and the intdiv() function has 0 as its second argument. Modulo Division by Zero The modulo operator (%) throws a DivisionByZeroError when the divisor is zero ? Modulo by zero Integer Division by Zero The intdiv() function also raises DivisionByZeroError when the divisor is zero ? ... Read More
ParseError class extends CompileError class and is thrown when PHP code inside a string passed to the eval() function contains syntax errors. The eval() function evaluates a given string as PHP code. If the code contains syntax errors, it throws a ParseError instead of causing a fatal error. Syntax eval ( string $code ) : mixed Parameters Parameter Description code Valid PHP code to be evaluated. Must not include opening/closing PHP tags and must end with semicolon. Valid code returns NULL, while syntax errors in the ... Read More
PHP's internal Error types are represented by classes that are inherited from Error class. The Error class implements Throwable interface and provides a structured way to handle different types of runtime errors. Error Class Properties message − The error message code − The error code file − The filename where the error happened line − The line where the error happened Error Class Methods __construct() − Construct the error object getMessage() − Gets the error ... Read More