performance.getEntries()

function use_PerformanceEntry_methods() {
  console.log("PerformanceEntry tests ...");

  if (performance.mark === undefined) {
    console.log("... performance.mark Not supported");
    return;
  }

  // Create some performance entries via the mark() method
  performance.mark("Begin");
  do_work(50000);
  performance.mark("End");
  performance.mark("Begin");
  do_work(100000);
  performance.mark("End");
  do_work(200000);
  performance.mark("End");

  // Use getEntries() to iterate through the each entry
  let p = performance.getEntries();
  for (var i=0; i < p.length; i++) {
    console.log("Entry[" + i + "]");
    check_PerformanceEntry(p[i]);
  }

  // Use getEntriesByType() to get all "mark" entries
  p = performance.getEntriesByType("mark");
  for (let i=0; i < p.length; i++) {
    console.log ("Mark only entry[" + i + "]: name = " + p[i].name +
         "; startTime = " + p[i].startTime +
         "; duration  = " + p[i].duration);
  }

  // Use getEntriesByName() to get all "mark" entries named "Begin"
  p = performance.getEntriesByName("Begin", "mark");
  for (let i=0; i < p.length; i++) {
    console.log ("Mark and Begin entry[" + i + "]: name = " + p[i].name +
         "; startTime = " + p[i].startTime +
         "; duration  = " + p[i].duration);
  }
}