// create div element by javascript with class
var div = document.createElement('div');
div.className = "div1";
Let suppose we are creating a div using javascript create element
// create a new div element
var newDiv = document.createElement("div");
// assigning class name to the new div
newDiv.className = "className";
elmnt.classList.add("YourClass");
var element =document.createElement("span");
element.className = "aClassName";
adding element classes in js