HTML Entity Decode

Question

How do I encode and decode HTML entities using JavaScript or JQuery?

var varTitle = "Chris' corner";

I want it to be:

var varTitle = "Chris' corner";

Answer 1

I recommend against using the jQuery code that was accepted as the answer. While it does not insert the string to decode into the page, it does cause things such as scripts and HTML elements to get created. This is way more code than we need. Instead, I suggest using a safer, more optimized function.

var decodeEntities = (function() {
  // this prevents any overhead from creating the object each time
  var element = document.createElement('div');

  function decodeHTMLEntities (str) {
    if(str && typeof str === 'string') {
      // strip script/html tags
      str = str.replace(/<script[^>]*>([\S\s]*?)<\/script>/gmi, '');
      str = str.replace(/<\/?\w(?:[^"'>]|"[^"]*"|'[^']*')*>/gmi, '');
      element.innerHTML = str;
      str = element.textContent;
      element.textContent = '';
    }

    return str;
  }

  return decodeHTMLEntities;
})();

http://jsfiddle.net/LYteC/4/

To use this function, just call decodeEntities("&") and it will use the same underlying techniques as the jQuery version will—but without jQuery's overhead, and after sanitizing the HTML tags in the input. See Mike Samuel's comment on the accepted answer for how to filter out HTML tags.

This function can be easily used as a jQuery plugin by adding the following line in your project.

jQuery.decodeEntities = decodeEntities;