> For the complete documentation index, see [llms.txt](https://laravel.palgle.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://laravel.palgle.com/knowledge-acquisition/throwable-tree.md).

# Exception + Error = Throwable Tree in PHP 7 over

* [PHP Throwable Tree](#php-throwable-tree)
  * [Introduction](#introduction)
  * [Example & Output](#example--output)
    * [ArithmeticError](#arithmeticerror)
    * [DivisionByZeroError](#divisionbyzeroerror)
    * [AssertionError](#assertionerror)
    * [ArgumentCountError](#argumentcounterror)
    * [TypeError](#typeerror)
  * [Runtime Exceptions](#runtime-exceptions)

## Introduction

PHP 7.x introduces new Throwable interface together Error and Exception.

```bash
Interface Throwable
+-- Error
|   +-- ArithmeticError
|   |   +-- DivisionByZeroError
|   +-- AssertionError
|   +-- CompileError (PHP 7.3 over)
|       +-- ParseError
|   +-- TypeError
|       +-- ArgumentCountError
+-- Exception
    +-- ClosedGeneratorException
    +-- DOMException
    +-- ErrorException
    +-- IntlException
    +-- LogicException
    |   +-- BadFunctionCallException
    |   |   +-- BadMethodCallException
    |   +-- DomainException
    |   +-- InvalidArgumentException
    |   +-- LengthException
    |   +-- OutOfRangeException
    +-- PharException
    +-- ReflectionException
    +-- RuntimeException
        +-- mysqli_sql_exception
        +-- OutOfBoundsException
        +-- OverflowException
        +-- PDOException
        +-- RangeException
        +-- UnderflowException
        +-- UnexpectedValueException
```

## Example & Output

### ArithmeticError

```php
<?php

intdiv(PHP_INT_MIN, -1);

// output
// Fatal error: Uncaught ArithmeticError: Division of PHP_INT_MIN by -1 is not an integer
```

### DivisionByZeroError

```php
<?php

$a = 3%0;

// output
// PHP Fatal error:  Uncaught DivisionByZeroError: Modulo by zero

$a = intdiv(3, 0); // 3/0 is not fire exception.

// output
// PHP Fatal error:  Uncaught DivisionByZeroError: Division by zero
```

### AssertionError

```php
<?php

ini_set('assert.exception', 1); //if without this, not exception but error

assert(2 < 1);

// output
// PHP Fatal error:  Uncaught AssertionError: assert(2 < 1) in...

```

### ArgumentCountError

```php
<?php

declare(strict_types=1); //if without this, not exception but error

$a = [1,2=>[3,4]];

count($a, COUNT_RECURSIVE, 'throw error');

// output
// PHP Fatal error:  Uncaught ArgumentCountError: count() expects at most 2 parameters, 3 given
```

### TypeError

```php
<?php

a('throw error');

function a(int $b) {}

// output
// PHP Fatal error:  Uncaught TypeError: Argument 1 passed to a() must be of the type int, string given
```

## Runtime Exceptions

| Name           | Example                                                                                                       |
| -------------- | ------------------------------------------------------------------------------------------------------------- |
| LogicException | [LogicException.php](https://github.com/cable8mm/laravel-tips/blob/main/src/ThrowableTree/LogicException.php) |