A case of how Js uses prototype to implement a custom array

Preface

Often in front-end interviews or communicating with other colleagues, when it comes to constructing the method of defining a constructor in JS, it is best to use a prototype: define the method The advantage of going to the prototype of the constructor is that the methods of the instance generated by the constructor all point to the index of a function, which can save memory.

This article mainly introduces to you the relevant content about Js using prototype custom array method, and shares it for your reference and study. I won’t say much below, let’s take a look at the detailed introduction.

Question

How to implement the following code:

[1,2,3,4,5].duplicator(); // [1,2,3,4,5,1,2,3,4,5]

Solution

Use the prototype attribute of array and customize theduplicator()method. The js code is as follows:

The display effect on the console is as follows:

Notes

When writing this codeArray.prototype.duplicatorBe careful not to add any brackets. This inside the function refers to the object that calls this method, which is array.

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