NodeJS Program to Require Cache Singleton with Explanation
NodeJS
Medium
Node Basics & Modules
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1 min read
83 words
This problem helps you practice core NodeJS fundamentals in a practical way. It builds intuition around require, cache, same. Let’s break it down step by step so you can implement it confidently.
Problem Statement
Show that requiring the same module twice returns the same instance.
Input Format
No input.
Output Format
Print true/false.
Constraints
Simulate require cache using a map.
Code Solution
This explanation is written for learning purposes and to help beginners understand the concept clearly.
const cache = new Map();
function requireSim(id, factory) {
if (cache.has(id)) return cache.get(id);
const mod = factory();
cache.set(id, mod);
return mod;
}
const a = requireSim('meetcode', () => ({ hits: 0 }));
const b = requireSim('meetcode', () => ({ hits: 999 }));
console.log(a === b);
Output Example
No sample I/O is provided for this question.
Common Mistakes
- Misreading input/output format.
- Not handling constraints and edge cases.
- Off-by-one errors in loops.
- Forgetting to reset variables between test cases (if any).
Solution Guide
Problem
Show that requiring the same module twice returns the same instance.
Input / Output
Constraints
Simulate require cache using a map.
Details
Common Mistakes
- Misreading input/output format.
- Not handling constraints and edge cases.
- Off-by-one errors in loops.
- Forgetting to reset variables between test cases (if any).
Official Solution
const cache = new Map();
function requireSim(id, factory) {
if (cache.has(id)) return cache.get(id);
const mod = factory();
cache.set(id, mod);
return mod;
}
const a = requireSim('meetcode', () => ({ hits: 0 }));
const b = requireSim('meetcode', () => ({ hits: 999 }));
console.log(a === b);
Solutions (0)
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