What is DOM in JavaScript and ten interview questions for DOM ?

• The Document Object Model(DOM) is a programing interface for web documents. It's represents an HTML or XML document as a tree of objects.Allowing a language like javascript to dynamically access and update the page's content, structure,and style.

• DOCUMENT - is the whole HTML loaded in the browser.It is entry point to access manipulate anything 0n the page.

• OBJECT - is the every part of the page is an object
  document - whole page object
  Elements (<div>,<h1>) - element objects
  Attributes(id,class) - attributes objects.

• MODEL - is a structured way (tree) to organize those objects

• TREE STRUCTURE : The browser converts HTML code into a hierarchical tree.The document is the root, while elements attributes,(like <div> or <p>), and text are "nodes" within that tree.

• The most common way to access an HTML element is to use the id of the element

Ten Interview Questions for DOM in JavaScript?

1. What is the DOM?

• The Document Object Model(DOM) is a programing interface for web documents. It's represents an HTML or XML document as a tree of objects.Allowing a language like javascript to dynamically access and update the page's content, structure,and style.

2. What is the document object?

• Document represents the entire web page and is the entry point to access and modify DOM elements.

3. How do you select an element in the DOM?

• Use document.getElementById("id") to select a single element using it's ID

4. What is the difference between getElementById and querySelector?

• getElementById - select by a ID only

• querySelector - (TBD)

5. How do you change the content of an element?

• Use element.innerHTML or element.textContent to modify text or HTML inside an element.

6. How do you change styles using JavaScript?

• Use element.style.color = "yellow" to change the styles dynamically .

7. What is an event in the DOM?

• An even is an action like a click,hover and key press that javascript can respond to.

8. How do you add an event listener? - (TBD)

9. How do you create and add a new element? - (TBD)

10. What is the difference between innerHTML and textContent?-(TBD)