The primary method of inserting JavaScript into an HTML page is via the <script> element.
There are six attributes for the <script> element:
| Attribute | Optional | Meaning |
|---|---|---|
| async | Optional | script should begin downloading immediately but should not prevent other actions such as downloading resources or waiting for other scripts to load. Valid only for external script files. |
| charset | Optional | The character set of the code specified using the src attribute. rarely used, because most browsers don't honor its value. |
| defer | Optional | execution of the script can safely be deferred until after the document's content has been completely parsed and displayed. Valid only for external scripts. |
| language | Deprecated | indicate the scripting language being used by the code block ("JavaScript", "JavaScript 1.2", or "VBScript"). Most browsers ignore this attribute. |
| src | Optional | an external file that contains code to be executed. |
| type | Optional | Replaces language; indicates the content type (MIME type) of the scripting language being used by the code block. Traditionally, this value has always been text/javascript", "text/javascript" and "text/ecmascript" are deprecated. This attribute is safe to omit, as "text/javascript" is assumed when missing. |