JavaScript Interview Question: var vs let vs const and Hoisting
Short answer: var is function-scoped and hoisted with the value undefined . let and const are block-scoped and can't be used before their de...
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React Interview Question: Controlled vs Uncontrolled Components
Short answer: a controlled input's value comes from React state and changes through onChange . An uncontrolled input keeps its own value in...
SQL Interview Question: What Is an Index and When Should You Not Use One?
Short answer: an index is a separate, sorted data structure (usually a B-tree) that maps column values to row locations, so the database can...
System Design Interview Question: Explain Caching Strategies at Scale
Caching appears in almost every design. Strong answers name the cache layer, the pattern, how data stays fresh and what happens when the cac...
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