How is "duplicate items" counted?

It's the number of extra occurrences beyond each item's first appearance, calculated as total items minus unique items. For example, in [a, b, b, b], "b" appears 3 times, so there are 2 duplicate occurrences (the 2nd and 3rd "b"), giving a duplicate count of 2.

What happens if there's a tie for longest or shortest item?

The first item encountered at that length is reported; ties aren't listed exhaustively.

Is item comparison for duplicates case-sensitive?

Yes, items are compared as exact strings, so "Apple" and "apple" are treated as different, distinct items.

How is this different from List Length Finder?

List Length Finder only reports item count and total characters for a quick check; this tool adds average length, longest/shortest items, and unique/duplicate counts for a fuller analysis.

List Statistics Generator - Analyze a List Online

Overview

Introduction

Understanding the shape of a list before working with it, its size, typical item length, and whether it has duplicates, saves time and catches data problems early.

List Statistics Generator produces a full statistical breakdown of a list in one pass: count, characters, averages, extremes, and duplicate analysis.

What Is List Statistics Generator?

This is the fuller sibling of List Length Finder, a comprehensive analysis tool that reports seven distinct statistics about a list in one report.

It covers size (item count, total characters, average length), extremes (longest and shortest item), and content quality (unique vs. duplicate item counts).

How List Statistics Generator Works

The input is split into items using your chosen separator, then item count and total character count are computed directly from the array.

Average length divides total characters by item count; longest and shortest are found with a single pass comparing each item's length; unique and duplicate counts come from building a `Set` of the items and comparing its size to the total item count.

When To Use List Statistics Generator

Use this before deduplicating, sorting, or otherwise transforming a list, to understand what you're working with.

It's especially useful for spotting unexpected duplicates or outlier-length items in a pasted dataset.

Often used alongside List Length Finder, List Truncator and Empty List Item Remover.

Features

Advantages

Covers size, extremes, and duplicate analysis in a single report rather than several separate tools.
Duplicate detection uses exact string comparison, so results are precise and predictable.
Works with any separator style.

Limitations

Duplicate and unique counts are case-sensitive and treat whitespace differences as distinct items; use List Item Trimmer first if that's not desired.
Ties for longest/shortest only report the first matching item, not every tied item.

Examples

Analyzing a list with a duplicate

Input

a, bb, ccc, bb

Output

Item count: 4
Total characters: 8
Average item length: 2.00
Longest item: "ccc" (3 chars)
Shortest item: "a" (1 chars)
Unique items: 3
Duplicate items: 1

"bb" appears twice, so there are 3 unique items among the 4 total, giving 1 duplicate occurrence.

Analyzing a list with no duplicates

Input

a, b, c

Output

Item count: 3
Total characters: 3
Average item length: 1.00
Longest item: "a" (1 chars)
Shortest item: "a" (1 chars)
Unique items: 3
Duplicate items: 0

All three items are distinct and the same length, so duplicates are 0 and the extremes are both the first item.

Best Practices & Notes

Best Practices

Run List Item Trimmer first if leading/trailing whitespace might be inflating your duplicate count with near-identical items.
Use the unique count together with List Length Finder's quick count to sanity-check large datasets before further processing.

Developer Notes

Longest/shortest use a single linear scan comparing `.length`; unique/duplicate counts use `new Set(items).size` compared against `items.length`, an O(n) approach that relies on exact string equality.

List Statistics Generator Use Cases

Auditing a dataset for duplicate entries before deduplication
Checking whether a list's item lengths are consistent (e.g. all IDs the same length)
Getting a quick statistical summary of pasted data before further processing

Common Mistakes

Assuming duplicate detection ignores case or whitespace; it doesn't, comparisons are exact.
Reading "duplicate items" as the count of items that have at least one duplicate, rather than the count of extra occurrences beyond the first.

Tips

If you need to actually remove duplicates rather than just count them, look for a dedicated deduplication tool in the site's other list-handling categories.
Combine with Empty List Item Remover first if blank items are skewing your average length statistic.

List Statistics Generator