Memoization in JavaScript

A simple introduction to Memoization in JavaScript, including its concept, workflow, and a practical example.

📄 About

This repository contains a PDF that explains how Memoization can improve the performance of functions by storing previously calculated results in a cache.

The PDF covers:

• What is Memoization?
• How Memoization works
• The role of caching
• A practical JavaScript implementation
• Executing a memoized function
• Comparing the first and subsequent function calls

💡 What is Memoization?

Memoization is an optimization technique commonly used in functional programming.

It stores the results of previous function calls in a cache. When the function is called again with the same input, the cached result can be returned instead of performing the calculation again.

Basic Flow

Function Call
     ↓
Check Cache
   ↙     ↘
Found    Not Found
  ↓         ↓
Return    Calculate
Result       ↓
          Store Result
              ↓
          Return Result

🧑‍💻 JavaScript Example

The PDF includes a simple memoization example:

const memoizeAddition = () => {
  let cache = {};

  return (value) => {
    if (value in cache) {
      console.log("Fetching from cache");
      return cache[value];
    } else {
      console.log("Calculating result");

      let result = value + 20;
      cache[value] = result;

      return result;
    }
  };
};

Usage

const addition = memoizeAddition();

console.log(addition(20)); // 40 → Calculating result
console.log(addition(20)); // 40 → Fetching from cache

On the first execution, the result is calculated and stored in the cache.

On the second execution with the same input, the stored result is returned directly.

📚 PDF

You can find the complete explanation in the PDF included in this repository:

📄 Download and Read Memoization in JavaScript

🎯 Key Takeaway

Memoization can reduce unnecessary repeated calculations by storing previously computed results and reusing them when the same input occurs again.

Calculate once, reuse when possible.

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Made for learning and understanding Memoization in JavaScript.