What happens if the list doesn't divide evenly by the group size?

The final chunk simply contains whatever items are left over, which may be fewer than the chosen group size. No items are dropped or padded to fill out the last group.

How is this different from List Item Pairer?

List Item Pairer is the same idea fixed at a group size of exactly 2. List Item Grouper generalizes that to any group size you choose, use it whenever you need chunks larger than a pair.

Can the glue string be different from the list's own separator?

Yes, the glue string used inside each chunk and the separator used between chunks in the output are configured independently, so you can, for example, join items within a chunk with a comma while separating chunks by newline.

List Item Grouper - Chunk a List Into Groups

Overview

Introduction

Batch processing, table layout, and CSV row-building often need a flat list rearranged into fixed-size groups rather than one item per line.

This tool chunks a list into groups of a chosen size and joins each group into a single output entry, so a long flat list becomes a compact grouped list.

What Is List Item Grouper?

A list transformer that partitions items into consecutive chunks of a chosen size N, generalizing simple pairing to any chunk size.

Each chunk's items are joined with a configurable glue string, and the resulting chunk-strings become the new output list, separated by your chosen list separator.

How List Item Grouper Works

The list is split into items using the resolved separator, then walked in steps of N, slicing out each consecutive chunk of up to N items.

Each chunk's items are joined with the glue string into a single string, and all chunk strings are rejoined into the final output using the list separator.

When To Use List Item Grouper

Use it when you need to batch a long list into fixed-size groups, for example turning a flat item list into rows of 3 for a grid layout.

It's also useful for building CSV-style rows from a flat column of values.

Often used alongside List Item Pairer, List Merger and List Sorter.

Features

Advantages

Works with any group size, not just pairs.
Separately configurable glue (within a chunk) and list separator (between chunks).
Handles uneven list lengths gracefully by shortening only the final chunk.

Limitations

Chunks are formed strictly by position in the original list; items are not reordered or filtered first.
A group size of 1 just re-joins each item alone, which is a valid but trivial use.
Very large group sizes relative to the list simply produce a single chunk containing everything.

Examples

Grouping five items into chunks of two

Input

a
b
c
d
e (size: 2, glue: "-")

Output

a-b
c-d
e

Four items form two full pairs; the fifth item becomes its own shorter final chunk.

Grouping into rows of three with a comma glue

Input

1
2
3
4
5
6 (size: 3, glue: ", ")

Output

1, 2, 3
4, 5, 6

Six items split evenly into two chunks of three.

Best Practices & Notes

Best Practices

Pick a group size that matches your target layout, for example 3 or 4 for a simple grid.
Use a distinct glue string from your list separator so chunk boundaries stay unambiguous.
Check the final chunk's length if your downstream process requires uniform-size groups.

Developer Notes

Implemented with a `for` loop stepping by `groupSize` over the split item array, using `Array.prototype.slice(i, i + groupSize)` to pull each chunk and `Array.prototype.join(glue)` to flatten it into a single string before the chunk strings are rejoined with the list separator.

List Item Grouper Use Cases

Batching a flat list into fixed-size rows for a grid or table
Building CSV rows of a chosen column count from a single-column export
Grouping a long tag list into readable clusters

Common Mistakes

Expecting every chunk to be exactly the same size when the list length isn't a multiple of the group size.
Using group size 0 or a negative number, which the tool rejects since it can't form chunks.
Confusing the glue string (within a chunk) with the output separator (between chunks).

Tips

Use List Item Pairer instead if you specifically want groups of exactly two.
Combine with List Item Counter Adder afterward to number each resulting group.

List Item Grouper