const searchInput = document.getElementById('searchInput');
const table = document.getElementById('filterTable');
const trArray = Array.prototype.slice.call(table.querySelectorAll('tbody tr'));

const filterTable = event => {
  const searchTerm = event.target.value.toLowerCase();
  trArray.forEach(row => {
    row.classList.add('hidden');
    const tdArray = Array.prototype.slice.call(row.getElementsByTagName('td'));
    tdArray.forEach(cell => {
      if (cell.innerText.toLowerCase().indexOf(searchTerm) > -1) {
        row.classList.remove('hidden');
      }
    });
  });
};

searchInput.addEventListener('keyup', filterTable, false);