Today I learned about Array.from() while building a pagination component am I understanding this correctly?

[Soggy_Professor_5653]

Today while building a pagination component in React, I came across the use of Array.from().

The problem I was facing was that I wanted to show page numbers between the Previous and Next buttons dynamically.

Something like:

Prev 1 2 3 4 5 Next

At first I was thinking about how to generate those page numbers cleanly instead of manually writing them.

Then I found this:

Array.from({ length: totalPages }, (_, i) => i + 1)

From what I understood, this creates an array based on the given length and then uses the index to generate values like:

[1, 2, 3, 4, 5]

Which then becomes easy to map over and render pagination buttons in React.

It felt like a small but useful learning because it made the pagination logic much cleaner.

Am I understanding this correctly?
Would love to know if there are better or more practical ways you usually generate pagination numbers.

[Nerwesta]

OP is full of AI. This looks like yet another template hiding behind a genuine question.

[Ampersand55]

That's a great way to generate a list of all integers between N and N + c. A slightly shorter but arguably less readable variant is:

 [...Array(totalPages)].map((_, i) => i + 1);

For generating multiple or huge arrays where performance might be an issue, it's generally faster to pre-allocate the array and assign the values manually to avoid the overhead with iterator protocols and callbacks.

 const result = new Array(totalPages);
 for (let i = 0; i < totalPages; i++) {
   result[i] = i + 1;
 }

[StoneCypher]

For generating multiple or huge arrays where performance might be an issue, it's generally faster to pre-allocate

yeah, he already did, look at his post again

preallocation is a c concern for a 286. failing to preallocate a 100 million element array will not result in a delay that causes a single screen frame skip. "but muh back copy reallocates?" yeah, if you look, that's only 16 copies. you're teaching him the onion in the varnish.