ul
li One
li.active Two
li.active Three
li Fourwindow.onload = () => {
const first = document.querySelector('.active:first-of-type');
console.log(first);
};window.onload = () => {
const all = document.querySelectorAll('.active');
const first = all[1];
const last = all[all.length-1];
console.log(first, last);
};
function firstAndLast( selector, context ) {
selector = typeof selector === 'string' ? selector.trim() : null;
if (!selector) throw new Error('Invalid selector!');
if (arguments.length === 1) {
context = document;
} else {
if (!(context.querySelectorAll)) throw new Error('Invalid context!');
}
var all = context.querySelectorAll(selector);
return [ all[0], all[all.length - 1] ];
}