Title: MimeType::__construct
Published: May 20, 2026

---

# MimeType::__construct( string $value )

## In this article

 * [Parameters](https://developer.wordpress.org/reference/classes/wordpress-aiclient-files-valueobjects-mimetype/__construct/?output_format=md#parameters)
 * [Source](https://developer.wordpress.org/reference/classes/wordpress-aiclient-files-valueobjects-mimetype/__construct/?output_format=md#source)
 * [Related](https://developer.wordpress.org/reference/classes/wordpress-aiclient-files-valueobjects-mimetype/__construct/?output_format=md#related)
 * [Changelog](https://developer.wordpress.org/reference/classes/wordpress-aiclient-files-valueobjects-mimetype/__construct/?output_format=md#changelog)

[ Back to top](https://developer.wordpress.org/reference/classes/wordpress-aiclient-files-valueobjects-mimetype/__construct/?output_format=md#wp--skip-link--target)

Constructor.

## 󠀁[Parameters](https://developer.wordpress.org/reference/classes/wordpress-aiclient-files-valueobjects-mimetype/__construct/?output_format=md#parameters)󠁿

 `$value`stringrequired

The MIME type value.

## 󠀁[Source](https://developer.wordpress.org/reference/classes/wordpress-aiclient-files-valueobjects-mimetype/__construct/?output_format=md#source)󠁿

    ```php
    public function __construct(string $value)
    {
        if (!self::isValid($value)) {
            throw new InvalidArgumentException(sprintf('Invalid MIME type: %s', $value));
        }
        $this->value = strtolower($value);
    }
    ```

[View all references](https://developer.wordpress.org/reference/files/wp-includes/php-ai-client/src/files/valueobjects/mimetype.php/)
[View on Trac](https://core.trac.wordpress.org/browser/tags/7.0/src/wp-includes/php-ai-client/src/Files/ValueObjects/MimeType.php#L101)
[View on GitHub](https://github.com/WordPress/wordpress-develop/blob/7.0/src/wp-includes/php-ai-client/src/Files/ValueObjects/MimeType.php#L101-L107)

## 󠀁[Related](https://developer.wordpress.org/reference/classes/wordpress-aiclient-files-valueobjects-mimetype/__construct/?output_format=md#related)󠁿

| Uses | Description | 
| [MimeType::isValid()](https://developer.wordpress.org/reference/classes/wordpress-aiclient-files-valueobjects-mimetype/isvalid/)`wp-includes/php-ai-client/src/Files/ValueObjects/MimeType.php` |

Checks if a MIME type string is valid.

  |

| Used by | Description | 
| [MimeType::fromExtension()](https://developer.wordpress.org/reference/classes/wordpress-aiclient-files-valueobjects-mimetype/fromextension/)`wp-includes/php-ai-client/src/Files/ValueObjects/MimeType.php` |

Creates a MimeType from a file extension.

  | 
| [File::determineMimeType()](https://developer.wordpress.org/reference/classes/wordpress-aiclient-files-dto-file/determinemimetype/)`wp-includes/php-ai-client/src/Files/DTO/File.php` |

Determines the MIME type from various sources.

  | 
| [File::detectAndProcessFile()](https://developer.wordpress.org/reference/classes/wordpress-aiclient-files-dto-file/detectandprocessfile/)`wp-includes/php-ai-client/src/Files/DTO/File.php` |

Detects the file type and processes it accordingly.

  |

## 󠀁[Changelog](https://developer.wordpress.org/reference/classes/wordpress-aiclient-files-valueobjects-mimetype/__construct/?output_format=md#changelog)󠁿

| Version | Description | 
| [0.1.0](https://developer.wordpress.org/reference/since/0.1.0/) | Introduced. |

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