Understanding PHP Throwable, Error, and Exception Classes in PHP 8.3

Error

Overview

Error is the base class for all internal PHP error classes.

Class Summary

<?php
class Error implements Throwable {
    /* properties */
    protected string $message = "";
    private string $string = "";
    protected int $code;
    protected string $file = "";
    protected int $line;
    private array $trace = [];
    private ?Throwable $previous = null;

    /* methods */
    public __construct(string $message = "", int $code = 0, ?Throwable $previous = null)
    final public getMessage(): string
    final public getPrevious(): ?Throwable
    final public getCode(): int
    final public getFile(): string
    final public getLine(): int
    final public getTrace(): array
    final public getTraceAsString(): string
    public __toString(): string
    private __clone(): void
}

Method Index

Error::__construct

— initialize error object Error::getMessage — retrieve error message Error::getPrevious — return previous Throwable Error::getCode — get error code Error::getFile — get file where error occurred Error::getLine — get line number of error Error::getTrace — obtain stack trace Error::getTraceAsString — stack trace as string Error::__toString — string representation of error Error::__clone — clone error object

Exception

Overview

Exception is the base class for all user‑level exceptions.

Class Summary

<?php
class Exception implements Throwable {
    /* properties */
    protected string $message = "";
    private string $string = "";
    protected int $code;
    protected string $file = "";
    protected int $line;
    private array $trace = [];
    private ?Throwable $previous = null;

    /* methods */
    public __construct(string $message = "", int $code = 0, ?Throwable $previous = null)
    final public getMessage(): string
    final public getPrevious(): ?Throwable
    final public getCode(): int
    final public getFile(): string
    final public getLine(): int
    final public getTrace(): array
    final public getTraceAsString(): string
    public __toString(): string
    private __clone(): void
}

Method Index

Exception::__construct

— exception constructor Exception::getMessage — retrieve exception message Exception::getPrevious — return previous Throwable Exception::getCode — get exception code Exception::getFile — file where exception was created Exception::getLine — line number in file where exception was created Exception::getTrace — obtain exception trace information Exception::getTraceAsString — trace as string Exception::__toString — convert exception to string Exception::__clone — clone exception

Exception Hierarchy Overview

A quick chart summarises the exception tree used in PHP versions.

Throwable
  ├── Error
  │     ├── ArithmeticError
  │     │       └── DivisionByZeroError
  │     ├── AssertionError
  │     ├── CompileError
  │     │       └── ParseError
  │     ├── TypeError
  │     │       └── ArgumentCountError
  │     ├── ValueError
  │     ├── UnhandledMatchError
  │     ├── FiberError
  │     └── Random\RandomError
  │           └── BrokenRandomEngineError
  │     └── DateError
  │           ├── DateObjectError
  │           └── DateRangeError
  └── Exception
        ├── ClosedGeneratorException
        ├── DOMException
        ├── ErrorException
        ├── IntlException
        ├── JsonException
        ├── LogicException
        │     ├── BadFunctionCallException
        │     │     └── BadMethodCallException
        │     ├── DomainException
        │     ├── InvalidArgumentException
        │     ├── LengthException
        │     └── OutOfRangeException
        ├── PharException
        ├── ReflectionException
        ├── RuntimeException
        │     ├── OutOfBoundsException
        │     ├── OverflowException
        │     ├── PDOException
        │     ├── RangeException
        │     ├── UnderflowException
        │     └── UnexpectedValueException
        ├── SodiumException
        ├── FiberExit
        ├── Random\RandomException
        └── DateException
              ├── DateInvalidTimeZoneException
              ├── DateInvalidOperationException
              ├── DateMalformedStringException
              ├── DateMalformedIntervalStringException
              └── DateMalformedPeriodStringException

PHP 8.3 Release Information

PHP 8.3 is the first release candidate for the upcoming PHP version and is now available for testing.

The first generally available PHP version is scheduled for release on November 23 this year; the RC indicates that all changes for PHP 8.3 have been implemented, leaving only polishing and bug fixes.

Before the final 8.3.0 release, five more release candidates will be issued, each two weeks apart.

PHP 8.3.0RC1 is tagged in the php-src repository, and a dedicated PHP-8.3 branch will be used for further 8.3 development, while the main branch now targets the upcoming PHP 8.4 release.