What is the difference between memoization and caching?

What is the difference between memoization and caching?

Memoization is a specific optimization technique that stores the results of expensive function calls and returns the cached result when the same inputs occur again. Caching, on the other hand, is a broader concept that involves storing data to speed up future requests, which can include various types of data, not just function results.

Can you give me an example of memoization in programming?

Sure! In JavaScript, you can create a memoized function like this:

function memoize(fn) {
    const cache = {};
    return function(...args) {
        const key = JSON.stringify(args);
        if (cache[key]) {
            return cache[key];
        }
        const result = fn(...args);
        cache[key] = result;
        return result;
    };
}

const fibonacci = memoize(n => n <= 1 ? n : fibonacci(n - 1) + fibonacci(n - 2));

This function caches the results of Fibonacci calculations.

How does caching improve performance?

Caching improves performance by reducing the time it takes to access data. Instead of recalculating or fetching data from a slower source (like a database or an API) every time, the system retrieves it from a faster storage layer, which significantly speeds up response times.

Are there any downsides to using caching?

Yes, there are some downsides to caching. It can lead to stale data if the underlying data changes and the cache isn't updated. Additionally, managing cache size and eviction policies can add complexity to your application.