What are some examples of selector memoization in programming?

Can you explain what selector memoization is?

Selector memoization is a technique used to optimize performance by caching the results of selector functions, so they don't need to be recalculated on every render.

Can you give me an example of how to implement selector memoization?

Sure! In a Redux application, you can use the reselect library to create memoized selectors. For example:

import { createSelector } from 'reselect';

const getItems = (state) => state.items;
const getFilter = (state) => state.filter;

const getVisibleItems = createSelector([
  getItems,
  getFilter
], (items, filter) => {
  return items.filter(item => item.visible === filter);
});

What are the benefits of using memoization?

The main benefits of using memoization include improved performance by reducing unnecessary calculations, and it helps in maintaining a consistent state by returning the same output for the same input.