method PerformanceObserver.prototype.observe
Usage in Deno
```typescript import { PerformanceObserver } from "node:node__perf_hooks.d.ts"; ```
PerformanceObserver.prototype.observe(options: { entryTypes: readonly EntryType[]; buffered?: boolean | undefined; } | { type: EntryType; buffered?: boolean | undefined; }): void
Subscribes the `PerformanceObserver` instance to notifications of new `PerformanceEntry` instances identified either by `options.entryTypes` or `options.type`:
```js
import {
performance,
PerformanceObserver,
} from 'node:perf_hooks';
const obs = new PerformanceObserver((list, observer) => {
// Called once asynchronously. `list` contains three items.
});
obs.observe({ type: 'mark' });
for (let n = 0; n < 3; n++)
performance.mark(`test${n}`);
```
void