How to use js scope chain

This article mainly introduces "how to use js scope chain". In daily operation, I believe many people have doubts about how to use js scope chain. The editor consulted all kinds of materials and sorted out simple and easy-to-use operation methods. I hope it will be helpful to answer the doubts about "how to use js scope chain". Next, please follow the editor to study!

1. When contemporary code is executed in an environment, it creates a functional domain chain.

2. The use of the scope chain allows variables to search up layer by layer along the scope chain until the overall environment.

3. The performance consumption of each layer of functional domain is huge, so it is necessary to reduce the number of search layers of objects at the top of the cache.

Example

Var color = "blue"; function changeColor () {var anotherColor = "red"; function swapColors () {var tempColor = anotherColor; anotherColor = color; color = tempColor; / / you can access color, anotherColor and tempColor} / / you can access color and anotherColor here, but not tempColor swapColors ();} / / you can only access colorchangeColor () At this point, the study on "how to use the js scope chain" is over. I hope to be able to solve your doubts. The collocation of theory and practice can better help you learn, go and try it! If you want to continue to learn more related knowledge, please continue to follow the website, the editor will continue to work hard to bring you more practical articles!