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Question 12 of 48medium

useMemo Hook

Memoizing expensive calculations.

What is useMemo?

useMemo memoizes the result of a calculation. It only recalculates when dependencies change.

When to Use

  • Expensive calculations
  • Referential equality for objects/arrays
  • Preventing unnecessary re-renders

Syntax

code.jsJavaScript
const memoizedValue = useMemo(() => computeExpensiveValue(a, b), [a, b]);