How to understand closures in js

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

1. There is a function b in function a, which can access the variables in function an and form a closure.

2. Closures can read variables inside other functions.

3. The closure is the bridge that connects the inside and outside of the function.

When you return a closure, the return function does not refer to any looping variables, or variables that will change later.

Example

Function count () {var arr = []; for (var I = 1; I