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Most people do not understand the knowledge points of this article "what is the role of javascript closures", so the editor summarizes the following contents, detailed contents, clear steps, and certain reference value. I hope you can get something after reading this article. Let's take a look at this "what is the role of javascript closures" article.

Usefulness description

1. You can read the variables inside the function outside the function, and the values of these variables are always kept in memory.

2. The closure will save the variables in the function in the memory, which increases the consumption of the memory, and the closure can not be abused. Otherwise, there will be problems with the performance of the web page, and the memory may leak in the lower version of IE.

Example

Function add () {var n = 5; / / here another function is returned within the function, and its internal member variable n is accessed to form the closure return function fn2 () {n = add (); console.log (fn ()); / / 6 console.log (fn ()); / / 7 console.log (fn ()). / / 8 above is the content of this article on "what is the role of javascript closures". I believe we all have some understanding. I hope the content shared by the editor will be helpful to you. If you want to know more about the relevant knowledge, please follow the industry information channel.

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