html - Append data within a class using pure Javascript -

i want append text within class using javascript, not using jquery. example:

<div class="a">     <div class ="b">         <div class="c">         </div>     </div> <div> 

after putting text within class="b", should like:

<div class="a">     <div class ="b">          text         <div class="c">         </div>     </div> <div> 

i want without using jquery.

using insertadjacenthtml() method:

var elements = document.getelementsbyclassname("b"); // elements class 'b'  (var = 0; < elements.length; i++) { // every element class 'b':      elements[i].insertadjacenthtml("afterbegin", "this text");      // insert text inside element  }

<div class="a">      <div class="b"><!-- text inserted here -->          <div class="c">          </div>      </div>  <div>