why removeAttribute function in javascript is not working?

• I am trying to remove class for specific div tag in HTML with below code.

document.getElementsByClassName("removableClass").removeAttribute('class');

But I got below error.

• Reason behind the error is getElementsByClassName will return us array of Objects
• So we need to specify which Object to be removed.
• By providing the index of the specific object or looping through all the objects we can remove the class.

• If we provide the specific index only that particular index object class will be removed like below.

  	document.getElementsByClassName("removableClass")[0].removeAttribute('class');

• If we loop through all the Objects we can remove classes from all the Objects as below.

  	for(var i=0;i<document.getElementsByClassName("removableClass").length;i++)
  	document.getElementsByClassName("removableClass")[i].removeAttribute('class');