Document labeled break and continue (C# 15)

[BillWagner]

Summary

Documents the C# 15 (.NET 11) labeled break and continue feature. Fixes #54653.

Scope is limited to the C# reference, publishing the speclet, and the What's new in C# 15 article.

Changes

• Language reference (jump-statements.md): extended the break and continue sections to cover labeled targets, clarified that continue targets loops only (not switch), and added the "only the immediately-nested statement is labeled" nuance. New snippet examples LabeledBreak and LabeledContinue in the jump-statements snippet project.
• What's new in C# 15 (csharp-15.md): new bullet + "Labeled break and continue" section.
• Speclet publishing: added the speclet to specification/toc.yml (Feature specifications → Statements) and to docfx.json (build include, title, and description metadata), following the pattern from Add closed hierarchies for C# 15, preview 5 #54128.

Notes for reviewers

• ⚠️ Draft — syntax not yet verified. The feature bits haven't shipped, so nothing compiles yet. The two new snippet .cs files use the speclet syntax and their // Output: blocks are reasoned by hand. These will be verified against early bits before the PR is marked ready.
• Speclet source: labeled-break-continue.md.

---

Internal previews

📄 File	🔗 Preview link
docs/core/whats-new/dotnet-11/overview.md	What's new in .NET 11
docs/csharp/language-reference/statements/jump-statements.md	Jump statements - break, continue, return, and goto
docs/csharp/specification/toc.yml	docs/csharp/specification/toc
docs/csharp/whats-new/csharp-15.md	What's new in C# 15

[Copilot]

Pull request overview

Documents the C# 15 labeled break and continue feature across the language reference, the C# 15 “What’s new” article, and the published feature specification (speclet).

Changes:

• Adds a new “Labeled break and continue” section to the C# 15 “What’s new” page.
• Extends the jump statements reference to explain labeled targets for break and continue, and adds new snippet examples.
• Publishes the speclet by wiring it into the C# specification TOC and docfx.json proposal metadata.

Reviewed changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
docs/csharp/whats-new/csharp-15.md	Adds a new section and TOC entry describing labeled break/continue.
docs/csharp/specification/toc.yml	Adds the proposal under Feature specifications → Statements.
docs/csharp/language-reference/statements/snippets/jump-statements/ContinueStatement.cs	Adds a labeled continue snippet example.
docs/csharp/language-reference/statements/snippets/jump-statements/BreakStatement.cs	Adds a labeled break snippet example.
docs/csharp/language-reference/statements/jump-statements.md	Updates break/continue documentation and references the new snippets.
docfx.json	Includes the new proposal in build inputs and adds title/description metadata.

[MatveevichOne]

@BillWagner, I've reviewed the PR and found the cause of the build failures:

Issue 1: CS8652 errors in snippets**
The labeled break/continue feature is a C# 15 preview feature, but the snippet project doesn't have LangVersion set to preview.

Fix: In docs/csharp/language-reference/statements/snippets/jump-statements/jump-statements.csproj, add:

<LangVersion>preview</LangVersion>
Issue 2: Non-self-contained example in csharp-15.md
The example uses grid.Height, grid.Width, grid.IsBlocked, and grid.IsGoal — these members aren't defined anywhere, so readers can't copy and run the code.
Fix: Replace the current example with this self-contained version using a 2D array:
csharp
string[,] grid = new string[,]
{
    { "Clear", "Clear", "Clear" },
    { "Clear", "Blocked", "Clear" },
    { "Clear", "Clear", "Goal" }
};

outer: for (int row = 0; row < grid.GetLength(0); row++)
{
    for (int column = 0; column < grid.GetLength(1); column++)
    {
        if (grid[row, column] == "Blocked")
        {
            Console.WriteLine($"Blocked at ({row}, {column}) — skipping to next day.");
            continue outer;
        }
        if (grid[row, column] == "Goal")
        {
            Console.WriteLine($"Goal found at ({row}, {column})!");
            break outer;
        }
        Console.WriteLine($"Processing ({row}, {column})");
    }
}
Issue 3 (optional): The snippet project targets net8.0. Consider updating to net9.0 or net10.0 since C# 15 corresponds to .NET 11. But adding LangVersion=preview is sufficient to fix the build.
Let me know if you need help applying these changes!

[BillWagner]

@BillWagner, I've reviewed the PR and found the cause of the build failures:

Thanks. I did know it was coming in preview, but hadn't updated the project files yet.

[gewarren]

I seem to remember an earlier PR that included code examples for labeled break/continue. Did you add links to that content? Also, if I remember correctly, that content explained nicely why you would use this, like instead of a bunch of conditional checks in each nested loop.

[gewarren]

When would you use two labels like that?