HTML DOM compareDocumentPosition() Method

The DOM compareDocumentPosition() method is used to compare two nodes and it returns an integer describing where they are positioned in the document.

Syntax:

node1.compareDocumentPosition(node2)

Return Value : This return an integer value and their meaning as follows :

1: This means that the two nodes do not belong to the same document.
2: This means that the two nodes node1 is positioned after node2.
4: This means that the two nodes node1 is positioned before node2.
8: This means that the two nodes node1 is positioned inside node2.
16: This means that the two nodes node2 is positioned inside node1.
32: This means that the two nodes have no relationship or they are two attributes on the same element.

Example-1: This will return only single value.

HTML

<!DOCTYPE html>
<html>
<style>
    div {
        width: 90%;
        height: 60%;
        padding: 20px;
        border: 2px solid green;
        font-weight: bold;
    }
      
    #ans {
        background-color: lightgrey;
        display: block;
        width: 100px;
        font-weight: bold;
        height: 20px;
        padding: 9px;
        color: green;
        float: right;
        margin-top: -20px;
    }
      
    #res {
        color: black;
    }
</style>
  
<body>
    <div>
        <p id="p1">
          This is first paragraph
        </p>
  
  
        
        <p id="p2">
          This is second paragraph
        </p>
  
  
        
        <p id="p3">
          This is third paragraph
        </p>
  
  
        
        <p id="ans">Answer : <span id="res"></span></p>
  
  
    </div>
    <br>
    
    <input type = button 
           onclick="myFunction()" value = 
           "Click Me.!" />
    <br>
  
    <script>
        function myFunction() {
            var x = p1.compareDocumentPosition(p2);
            document.getElementById("res").innerHTML = x;
        }
    </script>
  
</body>
  
</html>

Output:
Before click on the Button:

After click on the button:

Example-2: This will return combination of two values.

HTML

<!DOCTYPE html>
<html>
<style>
    div {
        width: 90%;
        height: 60%;
        padding: 20px;
        border: 2px solid green;
        font-weight: bold;
    }
      
    #ans {
        background-color: lightgrey;
        display: block;
        width: 100px;
        font-weight: bold;
        height: 20px;
        padding: 9px;
        color: green;
        float: right;
        margin-top: -20px;
    }
      
    #res {
        color: black;
    }
</style>
  
<body>
    <div>
        
        <p id="p1">This tutorial is on 
          <span id="p2">
             HTML | DOM compareDocumentPosition() Method
          </span> on GeeksforGeeks.!
        </p>
  
  
        
        <p id="ans">
          Answer : 
          <span id="res"></span>
        </p>
  
  
        
    </div>
    <br>
    
    <input type=button onclick="myFunction()" 
           value="Click Me.!" />
    <br>
  
    <script>
        function myFunction() {
            var x = p1.compareDocumentPosition(p2);
            document.getElementById("res").innerHTML = x;
        }
    </script>
  
</body>
  
</html>

Output:
Before Click on the Button:

After Click on the Button: Answer will be 20. ‘4’ means that first node is positioned before the second node and ’16’ second node is positioned inside the first node.

Note: The return value can be a combination of values. i.e. if the return value is 20 that means p2 is inside p1, ’16’ and p1 is positioned before p2 ‘4’.

Supported Browsers: