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This article mainly shows you "JavaScript how to avoid using for-in to traverse an array", the content is easy to understand, clear, hope to help you solve your doubts, the following let Xiaobian lead you to study and learn "JavaScript how to avoid using for-in to traverse an array" this article.

Avoid using for-in to traverse an array

Avoid using this approach:

Var sum = 0 for (var i in arrayNumbers) {sum + = arrayNumbers [I];}

A better way is:

Var sum = 0 for (var I = 0, len = arrayNumbers.length; I < len; iTunes +) {sum + = arrayNumbers [I];}

As an added bonus, the values of both the I and len variables are executed only once

Will be more efficient than the following:

For (var I = 0; I < arrayNumbers.length; iTunes +)

Why? Because arrayNumbers.length is counted every time it loops.

That's all of the article "how JavaScript avoids using for-in to traverse an array". Thank you for reading! I believe we all have a certain understanding, hope to share the content to help you, if you want to learn more knowledge, welcome to follow the industry information channel!

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