PerformanceObserverEntryList

{{APIRef("Performance API")}}{{AvailableInWorkers}}

The PerformanceObserverEntryList interface is a list of {{domxref("PerformanceEntry","performance events", '', 'true')}} that were explicitly observed via the {{domxref("PerformanceObserver.observe","observe()")}} method.

Instance methods

• {{domxref("PerformanceObserverEntryList.getEntries","PerformanceObserverEntryList.getEntries()")}}
  • : Returns a list of all explicitly observed {{domxref("PerformanceEntry")}} objects.
• {{domxref("PerformanceObserverEntryList.getEntriesByType","PerformanceObserverEntryList.getEntriesByType()")}}
  • : Returns a list of all explicitly observed {{domxref("PerformanceEntry")}} objects of the given entry type.
• {{domxref("PerformanceObserverEntryList.getEntriesByName","PerformanceObserverEntryList.getEntriesByName()")}}
  • : Returns a list of all explicitly observed {{domxref("PerformanceEntry")}} objects based on the given name and entry type.

Example

Using PerformanceObserverEntryList

In the following example, list is the PerformanceObserverEntryList object. The {{domxref("PerformanceObserverEntryList.getEntries","getEntries()")}} method is called to get all explicitly observed {{domxref("PerformanceEntry")}} objects which are "measure" and "mark" in this case.

function perfObserver(list, observer) {
  list.getEntries().forEach((entry) => {
    if (entry.entryType === "mark") {
      console.log(`${entry.name}'s startTime: ${entry.startTime}`);
    }
    if (entry.entryType === "measure") {
      console.log(`${entry.name}'s duration: ${entry.duration}`);
    }
  });
}
const observer = new PerformanceObserver(perfObserver);
observer.observe({ entryTypes: ["measure", "mark"] });

Specifications

{{Specifications}}

Browser compatibility

{{Compat}}