HTML Comments as strings

Reading HTML comments from a DOM tree with JavaScript is easy.

var nodes = document.body.childNodes,
    comments = [];

for (var i = 0; i < nodes.length; i++) {

    // if the nodeType is 8
    if (nodes[i].nodeType == 8) {
          
          // this is a comment
          comments.push(nodes[i]);
    }
}

Let's say that the comments array is not empty, so the type of comments[0] is a Comment. That's great but how can you read its content?

This is what the W3C DOM-Level-1 spec says. It implements the Comment interface.

interface Comment : CharacterData {
};

This does not really help us but don't despair. It also implements the Node interface.

  ...
  readonly attribute  DOMString            nodeName;
           attribute  DOMString            nodeValue;
  ...

Yes, it's read-only but you can get the comment as a string by using its nodeValue.

comments[0].nodeValue

W3C DOM-Level 3 specifies something called textContent. This can also do the job, you can read about them here, textContent vs. innerText