bookmarklet to sort school journal by classcode

index.js

javascript:(function(){
let tables = document.getElementsByTagName("table");
for (let table of tables) {
  let stores = [];
  const rows = table.tBodies[0].children;
  for (let row of rows) {
    const rowValue = row.children[0].innerText;
    const matches = rowValue.match(
      /^ +(\S+) +(\S+) +(\S+|\d\S\s{2}\S+) +(\d{1,2}\/\d{1,2}) .+(\d{2}-\d{2}) +(\d{2}:\d{2})$/,
    );
    if (matches) {
      const attendance = matches[4].split("/");
      if (attendance[0] !== attendance[1])
        row.style.cssText += "background-color: #f2dede;";
      const classcode = matches[3];
      stores.push([classcode, row]);
    }
  }
  stores.sort(function (x, y) {
    return x[0].localeCompare(y[0]);
  });
  for (var i = 0, len = stores.length; i < len; i++) {
    table.appendChild(stores[i][1]);
  }
  stores = null;
}
})()