1const allSpanElements = document.querySelectorAll('span');
2
3allSpanElements.forEach((spanElement) => {
4  	// Here comes the Code that should be executed on every Element, e.g.
5	spanElement.innerHTML = "This Content will appear on every span Element now";
6});

1/*The querySelector() method returns the first element that matches a specified 
2CSS selector(s) in the document. Note: The querySelector() method only returns 
3the first element that matches the specified selectors. To return all the 
4matches, use the querySelectorAll() method instead.*/
5
6// for example 
7
8//for class
9document.querySelector(".ClassName")
10
11// for id 
12document.querySelector("#ID")
13
14// etc.

1var test = document.querySelectorAll('input[value][type="checkbox"]:not([value=""])');

1var elements = document.getElementsByTagName("*");

1var matches = document.querySelectorAll("div.note, div.alert");
2