Is the end index inclusive or exclusive?

Exclusive, exactly like JavaScript's Array.prototype.slice: slice(1, 3) returns items at index 1 and 2, not index 3.

How do negative indices work?

They count backward from the end of the list, just like native slice: -1 refers to the last item, -2 to the second-to-last, and so on.

How is this different from Sublist Extractor?

Sublist Extractor uses simpler, human-friendly 1-based inclusive indices and clamps out-of-range values. List Slicer matches JavaScript's slice exactly: 0-based, exclusive end, and native negative-index support, for when you need precise developer-familiar behavior.

Can I omit the end index?

Yes, leaving it blank slices from the start index through the end of the list, matching slice(start) with no second argument.

List Slicer Online - JavaScript Array.slice() for Lists

Overview

Introduction

JavaScript developers already know exactly how Array.prototype.slice behaves, 0-based, exclusive end, negative indices from the end, and sometimes that's precisely the behavior needed on a plain-text list too.

List Slicer reproduces slice's exact semantics rather than a simplified, human-friendly approximation.

What Is List Slicer?

A tool that extracts a range of items from a list using the exact same rules as JavaScript's Array.prototype.slice(start, end).

It's the precise, developer-familiar counterpart to Sublist Extractor's simpler 1-based, clamped indexing.

How List Slicer Works

The input is split into items on the resolved separator, then Array.prototype.slice(start, end) is called directly on that array, with end left as undefined when not supplied.

Negative start or end values are handled by JavaScript's native slice behavior, counting backward from the array's length, with no custom clamping logic layered on top.

When To Use List Slicer

Use it whenever you need to reproduce exact JavaScript slice behavior on a plain-text list, for testing, teaching, or matching code output.

It's also useful for grabbing the last N items of a list using a negative start index, like slice(-3) for the last three items.

Often used alongside Sublist Extractor, List Splicer and List Rotator.

Features

Advantages

Behaves identically to native Array.prototype.slice, no surprises for anyone already familiar with JavaScript arrays.
Negative indices make grabbing "the last N items" a single, simple call.
Works with any configured separator, not just newline-delimited lists.

Limitations

0-based, exclusive-end indexing is less intuitive for non-developers than Sublist Extractor's 1-based inclusive approach.
Out-of-range indices aren't flagged as errors, native slice just returns an empty or partial result silently, matching JavaScript's own behavior.

Examples

Slice items 1 through 2 (0-based, exclusive end)

Input

a
b
c
d
e (start=1, end=3)

Output

b
c

slice(1, 3) returns the items at indices 1 and 2 ("b" and "c"); the item at index 3 is excluded.

Negative start grabs the last two items

Input

x,y,z,w (start=-2)

Output

z, w

start=-2 with no end counts two items back from the end of the list through to the end.

Best Practices & Notes

Best Practices

Use Sublist Extractor instead if you'd rather think in terms of "item 1 through item 5" than 0-based, exclusive-end ranges.
Use a negative start (like -1 or -3) as the simplest way to grab the last N items without knowing the exact list length.

Developer Notes

The lib function is a thin, direct wrapper around Array.prototype.slice(start, end) with no custom index normalization, so its behavior for edge cases (out-of-range indices, start > end, omitted end) matches the ECMAScript specification exactly rather than a reimplementation.

List Slicer Use Cases

Grabbing the last N items of a list with a negative start index
Reproducing exact JavaScript slice output for testing or teaching purposes
Extracting a 0-based, exclusive-end range that matches how a downstream script indexes the same data

Common Mistakes

Expecting the end index to be inclusive; it's exclusive, matching native slice, not Sublist Extractor's inclusive range.
Using 1-based indices out of habit; this tool is strictly 0-based like a JavaScript array.
Reaching for this tool when a simpler, human-friendly range was wanted; Sublist Extractor is usually the better fit for manual, non-code use.

Tips

Use a negative start with no end (like start=-5) as a quick way to say "the last 5 items."
Cross-check output against Sublist Extractor if you're unsure whether you want inclusive or exclusive end behavior.

List Slicer