CollectionInfo


CollectionInfo is a Visual Studio extension for C# developers that displays the index of an item when the caret is positioned on an element of a collection initializer.

Overview

When working with collection initializers such as:

List<int> source = [10, 5, 3];

CollectionInfo is designed to show the corresponding zero-based index:

10  → 0
5   → 1
3   → 2

The goal is to make collection positions easier to identify without manually counting elements.

Features

• Displays zero-based collection item indexes in the editor.
• Works with C# collection initializer syntax.
• Provides index information directly in the code editor.
• Uses Visual Studio's editor and C# language-service infrastructure.
• Designed to remain unobtrusive while programming.

Example


Given:

var numbers = new List<int>
{
    10,
    5,
    3
};

CollectionInfo can indicate:

10 → 0
5  → 1
3  → 2

Requirements

• Visual Studio Community 18.x or compatible Visual Studio 2026 installation.
• C# development workload.

Intended Use

CollectionInfo is useful when working with:

• List<T>
• Collection initializers
• Array-like collection data
• Large collections where manually counting positions is inconvenient
• Code where knowing an item's zero-based position is useful during development

License

MIT License