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JavaScript · Question 30

What is the DOM, and how does JavaScript interact with a web page through it?

Direct answer

The DOM is the browser's object representation of an HTML document; JavaScript uses DOM APIs to query, create, update, and listen to events on document nodes.

The Document Object Model (DOM) is a Web API, not part of the core ECMAScript language. The browser parses HTML into a tree of objects that scripts can work with.

  • Query: document.querySelector() returns the first matching element; querySelectorAll() returns all matches in a static NodeList.
  • Update: properties such as textContent, classList, attributes, and styles can change the rendered document.
  • Create/remove: createElement(), append(), remove(), and related APIs modify the tree.
  • Events: addEventListener() connects user or browser events to JavaScript handlers.