[Solved] How can you combine pure functions with memoization in Ruby without breaking purity? — Ans: Store results in a local hash passed as an argument. | Ruby

Ruby - Functional Patterns in Ruby

How can you combine pure functions with memoization in Ruby without breaking purity?

APrint cached results to console.

BStore results in a local hash passed as an argument.

CModify instance variables to save results.

DUse a global variable to cache results.

Step-by-Step Solution

Solution:

Step 1: Understand memoization and purity
Memoization caches results but must not cause side effects or depend on external state.
Step 2: Evaluate options
Store results in a local hash passed as an argument. uses local hash passed in, keeping function pure. Options B and C modify external state. Print cached results to console. causes side effect by printing.
Final Answer:
Store results in a local hash passed as an argument. -> Option B
Quick Check:
Memoization with local state keeps purity [OK]

Quick Trick: Pass cache as argument to keep function pure [OK]

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