How js splices arrays

This article mainly shows you "js how to assemble arrays", the content is easy to understand, clear, hope to help you solve your doubts, the following let the editor lead you to study and learn "js how to assemble arrays" this article.

Splicing array

If we want to concatenate several arrays, we can use the extension operator:

Const start = [1,2] const end = [5,6,7] const numbers = [9,... start,... end, 8] / / [9, 1, 2, 5, 6, 7, 8]

Or use the concat () method of the array:

Const start = [1,2,3,4] const end = [5,6,7] start.concat (end); / / [1,2,3,4,5,6,7]

But when using the concat () method, if the array that needs to be merged is large, the concat () function consumes a lot of memory when creating a separate new array. At this point, you can use the following methods to merge arrays:

Array.push.apply (start, end)

In this way, you can use less memory to a large extent.

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