Dom_manipulation.js

document.all;
// returns all the nodes inside the document object
 
document.contentType;
// returns the type of content contained. Most web pages should return "text/html"
 
document.URL;
// returns the URL of the document object
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document.getElementById()
//This method provides the quickest access to a node, but it requires that we know something 
//very specific about it — its id. Since IDs must be unique, this method only returns 
//one element.(If you have two elements with the same ID, this method returns 
//the first one — keep your IDs unique!)

      <div>
        <h5 id="greeting">Hello!</h5>
      </div>
      //we could find the h5 element with 
      document.getElementById('greeting')
      //Notice how the id that we pass to getElementById is identical to the id in <h5 id="greeting">
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document.getElementsByClassName()
//This method, as its name implies, finds elements by their className. Unlike id, 
//className does not need to be unique; as //such, this method returns an 
//HTMLCollection (basically a list of DOM nodes — note that it is not an array, even though it 
//has a length property) of all the elements with the given class. You can iterate over an HTMLCollection 
//with a simple for loop.

      <!-- the `className` attribute is called `class` in HTML -- it is a bummer -->
      <div>
        <div class="banner">
          <h1>Hello!</h1>
        </div>

        <div class="banner">
          <h1>Sup?</h1>
        </div>

        <div class="banner">
          <h5>Tinier heading</h5>
        </div>
      </div>
      //we could find all of the elements with className === 'banner' by calling 
      document.getElementsByClassName('banner')
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 document.getElementsByTagName()
//Suppose you dont know an elements ID but you do know its tag name (the tag name is 
//the main thing between the <>, e.g., 'div', 'span', 'h1', etc.). Since tag names arent unique, this method returns an //HTMLCollection of 0 to many nodes with the given tag.