How to set a value of the textarea without id by javascript?

Question

Typically we run javascript code to set any value:

document.getElementById(\'id_name\').value = \"...\";

But I have a page like this:

Answer 1

You can use the DOM properties and methods to get to that element from any fixed point (for instance, from your div that does have an id). In your case, it's dead easy:

document.getElementById('id_name').firstChild.firstChild.value = /* ... */;

...assuming that you've formatted that HTML for us and it really looks like this:

If that assumption isn't valid, then you have to do more work, because the firstChild may well be a Text node (containing the white space) rather than an Element. If so, it's still pretty easy with a helper function:

function firstElement(node) {
    while (node && node.nodeType !== 1) { // 1 = Element
        node = node.nextSibling;
    }
    return node;
}

var n = document.getElementById("id_name");
n = firstElement(n);
n = firstElement(n);
n.value = /* ... */;

This is why so many JavaScript DOM manipulation libraries have sprung up: Because common use-cases are frequently awkward when the DOM is used directly.

References:

• DOM2 Core
• DOM2 HTML
• DOM3 Core
• HTML5 Section 3 ("Semantics, Structures, and APIs of HTML documents")