getElementsByTagName() method

document.getElementsByTagName in JavaScript

The document.getElementsByTagName method in JavaScript generally return the elements of a specified tag name.

Here is the syntax of getElementsByTagName() method in JavaScript:

document.getElementsByTagName("name")

Please note that here name is required.

Below is an extremely simple example of document.getElementsByTagName() method in JavaScript:

Here, the total number of paragraphs used in the document will be counted using the document.getElementsByTagName() method.

<script type="text/javascript">  
function countpara(){  
var totalpara=document.getElementsByTagName("p");  
alert("total p tags are: "+totalpara.length);  
  }  
</script>  
<p>This is a pragraph</p>  
<p>Here the total number of paragraphs will be counted by getElementByTagName() method.</p>  
<p>Let's see the simple example</p>  
<button onclick="countpara()">count the paragraph</button>

Let's take another example to understand the document.getElementByTagName() method. Here is in this example the total number of h2 and h3 tags used in a document will be counted.

<script type="text/javascript">  
function counth2(){  
var totalh2=document.getElementsByTagName("h2");  
alert("total h2 tags are: "+totalh2.length);  
}  
function counth3(){  
var totalh3=document.getElementsByTagName("h3");  
alert("total h3 tags are: "+totalh3.length);  
}  
</script>  
<h2>This is h2 tag</h2>  
<h2>This is h2 tag</h2>  
<h3>This is h3 tag</h3>  
<h3>This is h3 tag</h3>  
<h3>This is h3 tag</h3>  
<button onclick="counth2()">count h2</button>  
<button onclick="counth3()">count h3</button>