How can get the text of a div tag using only javascript (no jQuery)

You'll probably want to try textContent instead of innerHTML.

Given innerHTML will return DOM content as a String and not exclusively the "text" in the div. It's fine if you know that your div contains only text but not suitable if every use case. For those cases, you'll probably have to use textContent instead of innerHTML

For example, considering the following markup:

<div id="test">
  Some <span class="foo">sample</span> text.
</div>

You'll get the following result:

var node = document.getElementById('test'),

htmlContent = node.innerHTML,
// htmlContent = "Some <span class="foo">sample</span> text."

textContent = node.textContent;
// textContent = "Some sample text."

See MDN for more details:

• textContent
• innerHTML

Because textContent is not supported in IE8 and older, here is a workaround:

var node = document.getElementById('test'),
var text  = node.textContent || node.innerText;
alert(text);

innerText does work in IE.