element.setAttribute(<name>, <value>);
// ex
var aElement = document.querySelector("a");
aElement.setAttribute("href", "https://isitchristmas.com/");
// same as <a href="https://isitchristmas.com/"></a>element.setAttribute(name, value);
var d = document.getElementById("d1");
d.setAttribute("align", "center");element.setAttribute(name, value);
element.setAttribute("style", "background-color: red;");const link = document.querySelector('a');
console.log(link.getAttribute('href'));
link.setAttribute('href', 'https://yandex.ru');
link.innerText = 'The Next Link';
const mssg = document.querySelector('p');
console.log(mssg.getAttribute('class'));
mssg.setAttribute('class', 'success');
mssg.setAttribute('style', 'color: green;');