HTML-encoding lost when attribute read from input field

Question

I’m using JavaScript to pull a value out from a hidden field and display it in a textbox. The value in the hidden field is encoded.

For example,

Answer 1

My pure-JS function:

/**
 * HTML entities encode
 *
 * @param {string} str Input text
 * @return {string} Filtered text
 */
function htmlencode (str){

  var div = document.createElement('div');
  div.appendChild(document.createTextNode(str));
  return div.innerHTML;
}

JavaScript HTML Entities Encode & Decode