Using JavaScript to Change Your Web Page Font Size

In this short JavaScript tutorial, Nurani guides you how to use JavaScript in changing the web page's font size. Maybe the JavaScripts to change font size are not new things on jsB@nk, because we shared you a lot of JavaScript codes, tutorials for things such as increase font size, javascript font style, javascript text size, ... But this JavaScript tutorial is also good practice to study, let go to the full post-page for details.


Sampled by © JavaScriptBank.com

Actually, almost all browsers have a feature to control the characters on the web pages you visit, by pressing the Ctrl key together with + (to zoom in) or - (to zoom out). But there is one other way of adding such a function "dynamic font size" on your site using javascript.

Here is a script that can be used to facilitate the visitors to control the font size of text on each page of your website/blog. This will be very useful for readers who struggle with small letters, and allow the person to enlarge the font size of your writing, so they are easier to read.

<script type="text/javascript">
var min=8;
var max=18;
function zoominLetter() {
   var p = document.getElementsByTagName('p');
   for(i=0;i<p.length;i++) {
      if(p[i].style.fontSize) {
         var s = parseInt(p[i].style.fontSize.replace("px",""));
      } else {
         var s = 12;
      }
      if(s!=max) {
         s += 1;
      }
      p[i].style.fontSize = s+"px"
   }
}
function zoomoutLetter() {
   var p = document.getElementsByTagName('p');
   for(i=0;i<p.length;i++) {
      if(p[i].style.fontSize) {
         var s = parseInt(p[i].style.fontSize.replace("px",""));
      } else {
         var s = 12;
      }
      if(s!=min) {
         s -= 1;
      }
      p[i].style.fontSize = s+"px"
   }
}
</script>

The script above will change the font size of text within the paragraph (tag <p>). If you want to use another tag, you can change the getElementsByTagName('p');

Of course, this script only works on the page with pixel sized fonts (letter-sized pixels (px)) compared with relative sized fonts (the relative size of the letters like: "em" and "%"). In addition, if the script does not find the font size of a paragraph, it will use the standard size, which is 12px.

How To Use :

Enter the above script on your blog page (either by typing in the tag <head> or by using .js file external and import). To call the function zoominLetter and zoomoutLetter you can use the following HTML code:

<a href="javascript:zoominLetter();">A</a>
<a href="javascript:zoomoutLetter();">a</a>

tips: You can change the text A | a with other signs, or replace it with a picture by using tags <img>.

Language
Translate this page to English Translate this page to French Translate this page to Vietnamese

Recent articles
The Possible Working Methods of Python Ideology
JavaScript Research Paper: 6 Writing Tips to Craft a Masterpiece
Learning How to Make Use of New Marketing Trends
5 Important Elements of an E-commerce Website
How To Create A Successful Prototype For Your PCB
WordPress Landing Page Conversion Essentials to Convert More
4 Development Hacks To Make Your Website Launch A Success
Why Data Recovery Software and Services are Important
Why Engineers Specializing in DevOps Are the Wave of the Future
The Ultimate Checklist for HTTP to HTTPS Migration


Top view articles
65 Free JavaScript Photo Gallery Solutions
Top 10 Beautiful Christmas Countdown Timers
Best Free Linux Web Programming Editors
Top 50 Most Addictive and Popular Facebook mini games
Top 10 Free Web Chat box Plug-ins and Add-ons
50+ Beautiful Resources of HTML Form using CSS and JavaScript
Top 10 Best JavaScript eBooks that Beginners should Learn
The Ultimate JavaScript Tutorial in Web Design
HTML5 Web Workers Multithreading in JavaScript
Learn more about JavaScript Inheritance with Tiny JavaScript Example Codes


Free JavaScript Tutorials & Articles
at www.JavaScriptBank.com