How does the location of a script tag in a page affect a JavaScript function that is defined in it?

by

Telling people to add <SCRIPT> only in the head sounds like a reasonable thing to do, but as others have said there are many reasons why this isn’t recommended or even practical – mainly speed and the way that HTML pages are generated dynamically.

This is what the HTML 4 spec says :

The SCRIPT element places a script
within a document. This element may
appear any number of times in the HEAD
or BODY of an HTML document.

And some sample HTML. Doesn’t it look pretty all formatted here 🙂

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN"
     "http://www.w3.org/TR/html4/strict.dtd">
<HTML>
<HEAD>
<TITLE>A document with SCRIPT</TITLE>
<META http-equiv="Content-Script-Type" content="text/tcl">
<SCRIPT type="text/vbscript" src="http://someplace.com/progs/vbcalc">
</SCRIPT>
</HEAD>
<BODY>
<SCRIPT type="text/javascript">
...some JavaScript...
</SCRIPT>
</BODY>
</HTML>

And something to look forward to in HTML 5 :

New async attribute in <SCRIPT> :

Note: There are ways [sic] a script can be
executed:

The async attribute is “true”: The
script will be executed asynchrously
with the rest of the page, so the
script will be executed while the page
continues the parsing.

The async attribute is “false”, but
the defer attribute is “true”: The
script will be executed when the page
is finished with the parsing.

More Related Contents:

  1. Javascript won’t output values from input box
  2. How to get current formatted date dd/mm/yyyy in Javascript and append it to an input [duplicate]
  3. HTML tag want to add both href and onclick working
  4. Full text search in HTML ignoring tags / &
  5. Make function wait until element exists
  6. anchor jumping by using javascript
  7. Storing arbitrary info in HTML tags for JavaScript?
  8. Class methods as event handlers in JavaScript?
  9. Calculate Position of selected text javascript/JQuery?
  10. Change onClick attribute with javascript
  11. Passing parameters to a JQuery function
  12. JavaScript button onclick not working
  13. javascript runs twice [closed]
  14. Tally value in dynamically generated textbox
  15. What is the correct syntax of ng-include?
  16. JavaScript function order: why does it matter?
  17. Streaming a video file to an html5 video player with Node.js so that the video controls continue to work?
  18. How to select multiple files with ?
  19. How to display image with JavaScript?
  20. How to close an open collapsed navbar when clicking outside of the navbar element in Bootstrap 3?
  21. How can I disable HREF if onclick is executed?
  22. Bootstrap Dropdown with Hover
  23. $http.get(…).success is not a function
  24. How to get a number value from an input field?
  25. HTML5 Video buffered attribute features
  26. How to make the HTML renders before the alert is triggered?
  27. Could a website force the browser to go into fullscreen mode?
  28. Why do two web pages have different localStorage? How can I fix this?
  29. How to apply background-color to a selected option?
  30. onChange event with contenteditable [duplicate]

Leave a Comment