Angular - Performance Optimization
What is the main purpose of using
trackBy in an ngFor directive in Angular?What is the main purpose of using trackBy in an ngFor directive in Angular?
easy📝 Conceptual Q11 of 15
Step-by-Step Solution
Solution:
Step 1: Understand what
ngFordoesngForrepeats a template for each item in a list, rendering them in the view.Step 2: Identify the role of
trackBytrackByhelps Angular know which items changed by uniquely identifying them, so it only updates those items instead of re-rendering the whole list.Final Answer:
To improve performance by uniquely identifying list items during updates -> Option AQuick Check:
TrackBy improves performance = C [OK]
Quick Trick: TrackBy helps Angular track items uniquely for faster updates [OK]
Common Mistakes:
- Thinking trackBy sorts or filters items
- Believing trackBy changes item styles
- Assuming trackBy removes duplicates
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