Скачать с ютуб Learn Angular 19 : 🔥 Master ngDoCheck() Life cycle hook method 🔥 | Real World Example | Episode 10 в хорошем качестве

Learn Angular 19 : 🔥 Master ngDoCheck() Life cycle hook method 🔥 | Real World Example | Episode 10

In this video, we will discuss about the ngDoCheck() life cycle hook method in angular 19 Introduction to ngDoCheck ngDoCheck is a lifecycle hook provided by Angular, called during every change detection run. It allows developers to implement custom change detection logic. Signature : ngDoCheck(): void This method is invoked every time Angular checks for changes in the component — whether or not anything has changed. Why and When to Use ngDoCheck? Angular provides default change detection with ngOnChanges, which works well for inputs. But ngDoCheck gives you finer control, especially when: 1. You need to detect changes not handled by Angular’s default detection. 2. You're using mutable objects/arrays, and their internal values change without changing the reference. 3. You want to track custom logic on every change detection cycle. ngOnChanges vs. ngDoCheck? Feature ngOnChanges ngDoCheck Trigger When @Input property changes Every change detection cycle Granularity Detects new input reference Can inspect object deeply Usage Simple use cases Complex, custom detection Performance Efficient Can be expensive if overused Performance Considerations? ngDoCheck runs frequently — potentially multiple times per second. Best Practices: 1. Avoid heavy computation in ngDoCheck. 2. Use it only when needed. 3. Consider KeyValueDiffers or IterableDiffers for better performance in tracking changes in objects and arrays. Summary for the Lecture Key Points to Highlight: ngDoCheck gives full control over change detection. Use it when Angular's default mechanisms (like ngOnChanges) are not sufficient. Be mindful of performance. Consider built-in differ helpers for complex objects/arrays.