setValue(prevValue => prevValue + number);setValue(prevValue => (prevValue + number).slice(0, 3));Promise
.all([...img].map(n => new Promise(r => n.complete ? r() : n.onload = r)))
.then(() => img.forEach(n => n.style.position = 'absolute'));const intervals = [ 1000, 2000, 500, 3000 ];
let interval = -1;
function newsRotator() {
const $news = $('.news');
const $hidden = $news.not(':visible');
const $next = $hidden.eq(Math.random() * $hidden.length | 0);
$news.hide();
$next.show();
interval = (interval + 1) % intervals.length;
setTimeout(newsRotator, intervals[interval]);
}
newsRotator();for(i = 0
i должна быть объявлена. Погуглите, что происходит, если выполнить присваивание необъявленной переменной.i<= n;newArr[i] = a[i];function arrayNtimes(a, n) {
const newArr = [];
for (let i = 0; i < n * a.length; i++) {
newArr[i] = a[i % a.length];
}
return newArr;
}const arrayNtimes = (a, n) => Array(n).fill(a).flat();element.insertAdjacentHTML('beforebegin', html);element.before(...new DOMParser().parseFromString(html, 'text/html').body.childNodes);
// или
element.parentNode.insertBefore(document.createRange().createContextualFragment(html), element);element.outerHTML = html + element.outerHTML;
const titleCase = str => str
.toLowerCase()
.split(' ')
.map(n => n[0].toUpperCase() + n.slice(1))
.join(' ');const titleCase = str => str
.toLowerCase()
.replace(/(?<=^| )./g, m => m.toUpperCase());const titleCase = str => Array
.from(str, (n, i) => n[i && str[i - 1] !== ' ' ? 'toLowerCase' : 'toUpperCase']())
.join``;('#app') new Vue({ router, store, render: h => h(App) }).$mount
$('.popup-link').magnificPopup({
midClick: true,
type: 'inline',
callbacks: {
open() {
const $slider = $('.slider');
if (!$slider.hasClass('slick-initialized')) {
$slider.slick({
infinite: true,
slidesToShow: 1,
dots: true,
});
}
$slider.slick('slickGoTo', +$(this).attr('index'));
},
},
});(() => {}) instanceof Object // true
Mixed Content: The page at 'https://jsfiddle.net/' was loaded over HTTPS, but requested an insecure script 'http://cdn.jsdelivr.net/npm/slick-carousel@1.8.1/slick/slick.min.js'. This request has been blocked; the content must be served over HTTPS.
const createTreeFromNestedSet = arr =>
[...arr].sort((a, b) => a.left - b.left).reduce((tree, n) => {
let curr = null;
let next = tree;
while (next) {
curr = next;
next = curr.children.find(c => c.left < n.left && c.right > n.right);
}
curr.children.push({ ...n, children: [] });
return tree;
}, { children: [] }).children[0];
const NestedSetTreeItem = ({ item }) => {
const [ showChildren, setShowChildren ] = React.useState(false);
const onClick = () => setShowChildren(v => !v);
return (
<div className="tree-item">
<span>{item.title}: {item.left} - {item.right}</span>
{item.children.length !== 0 ? (
<React.Fragment>
<button onClick={onClick}>{showChildren ? '-' : '+'}</button>
<div className={showChildren ? '' : 'hidden'}>
{item.children.map(n => <NestedSetTreeItem key={n.id} item={n} />)}
</div>
</React.Fragment>
) : null}
</div>
);
};
const NestedSetTree = ({ data }) => {
const tree = React.useMemo(() => createTreeFromNestedSet(data), [ data ]);
return <NestedSetTreeItem item={tree} />;
};
const data = [
{ title: 'Clothing', left: 1, right: 22 },
{ title: 'Men\'s', left: 2, right: 9 },
{ title: 'Women\'s', left: 10, right: 21 },
{ title: 'Suits', left: 3, right: 8 },
{ title: 'Slacks', left: 4, right: 5 },
{ title: 'Jackets', left: 6, right: 7 },
{ title: 'Dresses', left: 11, right: 16 },
{ title: 'Skirts', left: 17, right: 18 },
{ title: 'Blouses', left: 19, right: 20 },
{ title: 'Evening Gowns', left: 12, right: 13 },
{ title: 'Sun Dresses', left: 14, right: 15 },
].map((n, i) => ({ ...n, id: i + 1 }));
ReactDOM.render(<NestedSetTree data={data} />, document.getElementById('app'));<div id="app"></div>
const container = document;
const selector = 'input[type="checkbox"]';
const sumElements = elements =>
Array.prototype.reduce.call(elements, (acc, n) => acc + +n.value, 0);
const onSumChange = sum => console.log(sum);container.addEventListener('change', function({ target: t }) {
if (t.matches(selector)) {
onSumChange(sumElements(this.querySelectorAll(`${selector}:checked`)));
}
});
container.querySelector(selector).dispatchEvent(new Event('change', { bubbles: true }));const cb = container.querySelectorAll(selector);
let sum = sumElements(Array.prototype.filter.call(cb, n => n.checked));
const onChange = e => onSumChange(sum += e.target.value * [ -1, 1 ][+e.target.checked]);
cb.forEach(n => n.addEventListener('change', onChange));
onSumChange(sum);