PerformanceObserverEntryList
Note: This feature is available in Web Workers.
The PerformanceObserverEntryList interface is a list of performance events that were explicitly observed via the observe() method.
Instance methods
PerformanceObserverEntryList.getEntries()-
Returns a list of all explicitly observed
PerformanceEntryobjects. PerformanceObserverEntryList.getEntriesByType()-
Returns a list of all explicitly observed
PerformanceEntryobjects of the given entry type. PerformanceObserverEntryList.getEntriesByName()-
Returns a list of all explicitly observed
PerformanceEntryobjects based on the given name and entry type.
Example
Using PerformanceObserverEntryList
In the following example, list is the PerformanceObserverEntryList object. The getEntries() method is called to get all explicitly observed PerformanceEntry objects which are "measure" and "mark" in this case.
js
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"] });