How can you write a template expression that safely displays the length of an array items which might be null or undefined?

hard📝 component behavior Q8 of 15

Angular - Templates and Data Binding

How can you write a template expression that safely displays the length of an array items which might be null or undefined?

A{{ items?.length ?? 0 }}

B{{ items.length }}

C{{ items?.length || 'empty' }}

D{{ items.length ?? 0 }}

Step-by-Step Solution

Solution:

Step 1: Handle possible null or undefined array
Use safe navigation operator (?.) to avoid errors if items is null or undefined.
Step 2: Provide default value if length is undefined
The nullish coalescing operator (??) returns 0 if items?.length is null or undefined.
Final Answer:
{{ items?.length ?? 0 }} -> Option A
Quick Check:
Use ?. and ?? to safely access and default values [OK]

Quick Trick: Combine ?. and ?? to safely access and default values [OK]

Common Mistakes:

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