What is memoization in JavaScript and how does it work?

What is memoization in JavaScript and how does it work?

Memoization is an optimization technique used to speed up function calls by caching previously computed results.

Can you show me an example of memoization in JavaScript?

Sure! Here's a simple example:

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 => {
    if (n <= 1) return n;
    return fibonacci(n - 1) + fibonacci(n - 2);
});

How does this improve performance?

By caching results, memoization avoids redundant calculations, significantly improving performance for functions with overlapping subproblems.

Are there any downsides to using memoization?

Yes, memoization can increase memory usage due to caching, and it may not be beneficial for functions with high variability in input.