下列常量由此扩展定义，且仅在此扩展编译入 PHP 或在运行时动态载入时可用。
| Constant | Value | Description |
|---|---|---|
DOM_PHP_ERR
(int)
|
0 | Error code not part of the DOM specification. Meant for PHP errors. |
DOM_INDEX_SIZE_ERR
(int)
|
1 | If index or size is negative, or greater than the allowed value. |
DOMSTRING_SIZE_ERR
(int)
|
2 | If the specified range of text does not fit into a DOMString. |
DOM_HIERARCHY_REQUEST_ERR
(int)
|
3 | If any node is inserted somewhere it doesn't belong |
DOM_WRONG_DOCUMENT_ERR
(int)
|
4 | If a node is used in a different document than the one that created it. |
DOM_INVALID_CHARACTER_ERR
(int)
|
5 | If an invalid or illegal character is specified, such as in a name. |
DOM_NO_DATA_ALLOWED_ERR
(int)
|
6 | If data is specified for a node which does not support data. |
DOM_NO_MODIFICATION_ALLOWED_ERR
(int)
|
7 | If an attempt is made to modify an object where modifications are not allowed. |
DOM_NOT_FOUND_ERR
(int)
|
8 | If an attempt is made to reference a node in a context where it does not exist. |
DOM_NOT_SUPPORTED_ERR
(int)
|
9 | If the implementation does not support the requested type of object or operation. |
DOM_INUSE_ATTRIBUTE_ERR
(int)
|
10 | If an attempt is made to add an attribute that is already in use elsewhere. |
DOM_INVALID_STATE_ERR
(int)
|
11 | If an attempt is made to use an object that is not, or is no longer, usable. |
DOM_SYNTAX_ERR
(int)
|
12 | If an invalid or illegal string is specified. |
DOM_INVALID_MODIFICATION_ERR
(int)
|
13 | If an attempt is made to modify the type of the underlying object. |
DOM_NAMESPACE_ERR
(int)
|
14 | If an attempt is made to create or change an object in a way which is incorrect with regard to namespaces. |
DOM_INVALID_ACCESS_ERR
(int)
|
15 | If a parameter or an operation is not supported by the underlying object. |
DOM_VALIDATION_ERR
(int)
|
16 | If a call to a method such as insertBefore or removeChild would make the Node invalid with respect to "partial validity", this exception would be raised and the operation would not be done. |