HTML - tags - script tag

revision: January 28, 2025

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"script" tag : embed a client-side script

The <script> tag is used to embed a client-side script (JavaScript). The <script> element either contains scripting statements, or it points to an external script file through the "src attribute". Common uses for JavaScript are image manipulation, form validation, and dynamic changes of content.

Attributes: the <script> element supports the global attributes. Specific attributes are:

async ; value: async;

specifies that the script is downloaded in parallel to parsing the page, and executed as soon as it is available (before parsing completes) (only for external scripts).

crossorigin ; value: anonymous, use-credentials;

sets the mode of the request to an HTTP CORS Request.

defer ; value: defer;

specifies that the script is downloaded in parallel to parsing the page, and executed after the page has finished parsing (only for external scripts).

integrity ; value: filehash;

allows a browser to check the fetched script to ensure that the code is never loaded if the source has been manipulated.

nomodule ; value: True, False:

specifies that the script should not be executed in browsers supporting ES2015 modules.

referrerpolicy ; value: no-referrer, no-referrer-when-downgrade, origin, origin-when-cross-origin, same-origin, strict-origin, strict-origin-when-cross-origin, unsafe-url;

specifies which referrer information to send when fetching a script.

src ; value: URL;

specifies the URL of an external script file.

type ; value: scripttype;

specifies the media type of the script.

syntax

<script> . . . </script>

some examples

                    <p class="spec" id="demo"></p>
                    <script>
                        document.getElementById("demo").innerHTML = "Hello JavaScript!";
                    </script> 
                

                    <span style="margin-left:4vw;" onmouseover="myAlert();">
                        Bring your mouse here to see an alert
                    </span>
                    <script type="text/javascript">
                        function myAlert(){
                            alert("I am an event handler....");
                            return;
                        }
                    </script>