const getBaseURL = url => url.replace(/[?#].*$/, '');
getBaseURL('http://url.com/page?name=Adam&surname=Smith');
// 'http://url.com/page'
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const isAbsoluteURL = str => /^[a-z][a-z0-9+.-]*:/.test(str);
isAbsoluteURL('https://google.com'); // true
isAbsoluteURL('ftp://www.myserver.net'); // true
isAbsoluteURL('/foo/bar'); // false
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const getURLParameters = url =>
  (url.match(/([^?=&]+)(=([^&]*))/g) || []).reduce(
    (a, v) => (
      (a[v.slice(0, v.indexOf('='))] = v.slice(v.indexOf('=') + 1)), a
    ),
    {}
  );
getURLParameters('google.com'); // {}
getURLParameters('http://url.com/page?name=Adam&surname=Smith');
// {name: 'Adam', surname: 'Smith'}
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const elementContains = (parent, child) =>
  parent !== child && parent.contains(child);
elementContains(
  document.querySelector('head'),
  document.querySelector('title')
);
// true
elementContains(document.querySelector('body'), document.querySelector('body'));
// false
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const getAncestors = el => {
  let ancestors = [];
  while (el) {
    ancestors.unshift(el);
    el = el.parentNode;
  }
  return ancestors;
};
getAncestors(document.querySelector('nav'));
// [document, html, body, header, nav]
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const smoothScroll = element =>
  document.querySelector(element).scrollIntoView({
    behavior: 'smooth'
  });
smoothScroll('#fooBar'); // scrolls smoothly to the element with the id fooBar
smoothScroll('.fooBar');
// scrolls smoothly to the first element with a class of fooBar
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const onClickOutside = (element, callback) => {
  document.addEventListener('click', e => {
    if (!element.contains(e.target)) callback();
  });
};
onClickOutside('#my-element', () => console.log('Hello'));
// Will log 'Hello' whenever the user clicks outside of #my-element
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const UUIDGeneratorBrowser = () =>
  ([1e7] + -1e3 + -4e3 + -8e3 + -1e11).replace(/[018]/g, c =>
    (
      c ^
      (crypto.getRandomValues(new Uint8Array(1))[0] & (15 >> (c / 4)))
    ).toString(16)
  );
UUIDGeneratorBrowser(); // '7982fcfe-5721-4632-bede-6000885be57d'
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const getSelectedText = () => window.getSelection().toString();
getSelectedText(); // 'Lorem ipsum'
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const copyToClipboard = str => {
  if (navigator && navigator.clipboard && navigator.clipboard.writeText)
    return navigator.clipboard.writeText(str);
  return Promise.reject('The Clipboard API is not available.');
};
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const addStyles = (el, styles) => Object.assign(el.style, styles);
addStyles(document.getElementById('my-element'), {
  background: 'red',
  color: '#ffff00',
  fontSize: '3rem'
});
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const fullscreen = (mode = true, el = 'body') =>
  mode
    ? document.querySelector(el).requestFullscreen()
    : document.exitFullscreen();
fullscreen(); // Opens `body` in fullscreen mode
fullscreen(false); // Exits fullscreen mode
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<form>
  <label for="username">Username:</label>
  <input id="username" name="username">
  <label for="password">Password:</label>
  <input id="password" name="password" type="password">
  <span id="password-message" style="display: none">Caps Lock is on</span>
</form>
const el = document.getElementById('password');
const msg = document.getElementById('password-message');
el.addEventListener('keyup', e => {
  msg.style = e.getModifierState('CapsLock')
    ? 'display: block'
    : 'display: none';
});
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const isDateValid = (...val) => !Number.isNaN(new Date(...val).valueOf());
isDateValid('December 17, 1995 03:24:00'); // true
isDateValid('1995-12-17T03:24:00'); // true
isDateValid('1995-12-17 T03:24:00'); // false
isDateValid('Duck'); // false
isDateValid(1995, 11, 17); // true
isDateValid(1995, 11, 17, 'Duck'); // false
isDateValid({}); // false
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const getColonTimeFromDate = date => date.toTimeString().slice(0, 8);
getColonTimeFromDate(new Date()); // '08:38:00'
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const getTimestamp = (date = new Date()) => Math.floor(date.getTime() / 1000);
getTimestamp(); // 1602162242
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const detectLanguage = (defaultLang = 'en-US') =>
  navigator.language ||
  (Array.isArray(navigator.languages) && navigator.languages[0]) ||
  defaultLang;
detectLanguage(); // 'nl-NL'
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const prefersDarkColorScheme = () =>
  window &&
  window.matchMedia &&
  window.matchMedia('(prefers-color-scheme: dark)').matches;
prefersDarkColorScheme(); // true
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