Ace the Angular Interview 2025 – Code Your Way to Success!

The method used to append a child node to a DOM element is `appendChild()`. This method is part of the Node interface in the Document Object Model (DOM) and allows developers to add a new child node to an existing node in the document tree. When using `appendChild()`, the specified child node is moved if it is already present in the document, as nodes can only exist in one location in the DOM hierarchy.

For instance, if you have a parent element and you want to add a new child element, you can call `parentElement.appendChild(newChildElement)`. This action will add `newChildElement` as the last child of `parentElement`.

In contrast, the other choices do not exist as standard methods in the DOM API. `insertChild()` is not a valid method name; it does not exist within the DOM methods. `addChild()` is typically used in specific libraries or frameworks but is not part of the standard web API. `attachChild()` similarly is not a recognized method in the context of DOM manipulation. Thus, `appendChild()` remains the correct and widely accepted method for appending child nodes in the DOM.