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This article mainly introduces how to use the find function in JavaScript, has a certain reference value, interested friends can refer to, I hope you can learn a lot after reading this article, the following let Xiaobian take you to understand it.

Find function

Syntax: arr.find (callbackFn [, thisArg])

Method function: returns the value of the first element in the array that satisfies the provided test function. Otherwise, undefined is returned.

Return: the value of the first element in the array that satisfies the provided test function, otherwise it returns undefined.

Custom function: myFind.

Array.prototype.myFind = function (callbackFn, thisArg) {if (typeof callbackFn! = = 'function') throw (' callbackFn parameter must be a function'); let element = this, len = element & & element.length | | 0; if (! thisArg) thisArg = element; for (let index = 0; index < len; index++) {if (callbackFn.call (thisArg, element [index], index, element)) {return element [index] } return} Thank you for reading this article carefully. I hope the article "how to use the find function in JavaScript" shared by the editor will be helpful to you. At the same time, I also hope you will support us and pay attention to the industry information channel. More related knowledge is waiting for you to learn!

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