Answer
V8 creates hidden classes for optimized object access. Changing object shape dynamically causes deoptimization, harming performance. Keep object structures consistent.
Quick Answer
V8 assigns a hidden class to each object based on its shape (property names and order). Objects with the same shape share a hidden class and get optimized machine code together. If you add properties in different orders or add properties after creation, V8 assigns a new hidden class — deoptimizing those objects. Always initialize all properties in the constructor and in the same order.
S
SugharaIQ Editorial Team
Verified Answer
This answer has been peer-reviewed by industry experts holding senior engineering roles to ensure technical accuracy and relevance for modern interview standards.
Want to bookmark, take notes, or join discussions?
Sign in to access all features and personalize your learning experience.
Source: SugharaIQ