You have a component rendering a large list with *ngFor using Default change detection. Which approach improves performance without switching to OnPush?
hard📝 component behavior Q8 of 15
Angular - Change Detection
You have a component rendering a large list with *ngFor using Default change detection. Which approach improves performance without switching to OnPush?
AManually call detectChanges() after every update
BImplement a trackBy function to optimize list rendering
CWrap the list in a separate component with OnPush strategy
DUse two-way binding on all list items
Step-by-Step Solution
Solution:
Step 1: Understand Default Strategy
Default runs change detection frequently, which can be costly for large lists.
Step 2: Optimize with trackBy
Using trackBy helps Angular identify items uniquely, reducing DOM manipulations.
Step 3: Evaluate Options
Only trackBy improves performance without changing detection strategy.
Final Answer:
Implement a trackBy function to optimize list rendering -> Option B
Quick Check:
trackBy reduces DOM updates in large lists [OK]
Quick Trick:Use trackBy with *ngFor to boost performance [OK]
Common Mistakes:
MISTAKES
Thinking detectChanges() improves performance
Assuming wrapping in OnPush component is allowed
Using two-way binding unnecessarily
Master "Change Detection" in Angular
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