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Adding code samples

You can add inline code snippets or code blocks. Code blocks support meta options for syntax highlighting, titles, line highlighting, icons, and more.

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Inline code

To denote a word or phrase as code, enclose it in backticks (`). 
To denote a `word` or `phrase` as code, enclose it in backticks (`).

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Code blocks

Use fenced code blocks by enclosing code in three backticks. Code blocks are copyable, and if you have the assistant enabled, users can ask AI to explain the code. Specify the programming language for syntax highlighting and to enable meta options. Add any meta options, like a title or icon, after the language. 
class HelloWorld {
    public static void main(String[] args) {
        System.out.println("Hello, World!");
    }
}

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Code block options

Add meta options to your code blocks to customize their appearance.
You must specify a programming language for a code block before adding any other meta options.

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Option syntax

  • String and boolean options: Wrap with "", '', or no quotes.
  • Expression options: Wrap with {}, "", or ''.

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Syntax highlighting

Enable syntax highlighting by specifying the programming language after the opening backticks of a code block. We use Shiki for syntax highlighting and support all available languages. See the full list of languages in Shiki’s documentation. Customize code block themes globally using styling.codeblocks in your docs.json file. Set simple themes like system or dark, or configure custom Shiki themes for light and dark modes. See Settings for configuration options. 
class HelloWorld {
    public static void main(String[] args) {
        System.out.println("Hello, World!");
    }
}

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Twoslash

In JavaScript and TypeScript code blocks, use twoslash to enable interactive type information. Users can hover over variables, functions, and parameters to see types and errors like in an IDE. 
type  = "cat" | "dog" | "hamster";

function (: string, : ) {
  return `${} the ${} is now adopted!`;
}

// Hover to see the inferred types
const  = ("Mintie", "cat");

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Title

Add a title to label your code example. Use title="Your title" or a string on a single line. 
const hello = "world";

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Icon

Add an icon to your code block using the icon property. See Icons for all available options. 
const hello = "world";

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Line highlighting

Highlight specific lines in your code blocks using highlight with the line numbers or ranges you want to highlight. 
const greeting = "Hello, World!";
function sayHello() {
  console.log(greeting);
}
sayHello();

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Line focusing

Focus on specific lines in your code blocks using focus with line numbers or ranges. 
const greeting = "Hello, World!";
function sayHello() {
  console.log(greeting);
}
sayHello();

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Show line numbers

Display line numbers on the left side of your code block using lines. 
const greeting = "Hello, World!";
function sayHello() {
  console.log(greeting);
}
sayHello();

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Expandable

Allow users to expand and collapse long code blocks using expandable. 
from datetime import datetime, timedelta
from typing import Dict, List, Optional
from dataclasses import dataclass

@dataclass
class Book:
title: str
author: str
isbn: str
checked_out: bool = False
due_date: Optional[datetime] = None

class Library:
    def __init__(self):
        self.books: Dict[str, Book] = {}
        self.checkouts: Dict[str, List[str]] = {} # patron -> list of ISBNs

    def add_book(self, book: Book) -> None:
        if book.isbn in self.books:
            raise ValueError(f"Book with ISBN {book.isbn} already exists")
        self.books[book.isbn] = book

    def checkout_book(self, isbn: str, patron: str, days: int = 14) -> None:
        if patron not in self.checkouts:
            self.checkouts[patron] = []

        book = self.books.get(isbn)
        if not book:
            raise ValueError("Book not found")

        if book.checked_out:
            raise ValueError("Book is already checked out")

        if len(self.checkouts[patron]) >= 3:
            raise ValueError("Patron has reached checkout limit")

        book.checked_out = True
        book.due_date = datetime.now() + timedelta(days=days)
        self.checkouts[patron].append(isbn)

    def return_book(self, isbn: str) -> float:
        book = self.books.get(isbn)
        if not book or not book.checked_out:
            raise ValueError("Book not found or not checked out")

        late_fee = 0.0
        if datetime.now() > book.due_date:
            days_late = (datetime.now() - book.due_date).days
            late_fee = days_late * 0.50

        book.checked_out = False
        book.due_date = None

        # Remove from patron's checkouts
        for patron, books in self.checkouts.items():
            if isbn in books:
                books.remove(isbn)
                break

        return late_fee

    def search(self, query: str) -> List[Book]:
        query = query.lower()
        return [
            book for book in self.books.values()
            if query in book.title.lower() or query in book.author.lower()
        ]

def main():
    library = Library()

    # Add some books
    books = [
        Book("The Hobbit", "J.R.R. Tolkien", "978-0-261-10295-4"),
        Book("1984", "George Orwell", "978-0-452-28423-4"),
    ]

    for book in books:
        library.add_book(book)

    # Checkout and return example
    library.checkout_book("978-0-261-10295-4", "patron123")
    late_fee = library.return_book("978-0-261-10295-4")
    print(f"Late fee: ${late_fee:.2f}")

if __name__ == "__main__":
    main()

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Wrap

Enable text wrapping for long lines using wrap. This prevents horizontal scrolling and makes long lines easier to read. 
const greeting =
  "Hello, World! I am a long line of text that will wrap to the next line.";
function sayHello() {
  console.log(greeting);
}
sayHello();

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Diff

Show a visual diff of added or removed lines in your code blocks. Added lines are highlighted in green and removed lines are highlighted in red. To create diffs, add these special comments at the end of lines in your code block:
  • // [!code ++]: Mark a line as added (green highlight).
  • // [!code --]: Mark a line as removed (red highlight).
For multiple consecutive lines, specify the number of lines after a colon:
  • // [!code ++:3]: Mark the current line plus the next two lines as added.
  • // [!code --:5]: Mark the current line plus the next four lines as removed.
The comment syntax must match your programming language (for example, // for JavaScript or # for Python). 
const greeting = "Hello, World!"; 
function sayHello() {
  console.log("Hello, World!"); 
  console.log(greeting); 
}
sayHello();

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CodeBlock component

Use the <CodeBlock> component in custom React components to programmatically render code blocks with the same styling and features as markdown code blocks.

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Props

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language
string
The programming language for syntax highlighting.
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filename
string
The filename to display in the code block header.
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icon
string
The icon to display in the code block header. See Icons for available options.
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lines
boolean
Whether to show line numbers.
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wrap
boolean
Whether to wrap the code block.
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expandable
boolean
Whether to expand the code block.
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highlight
string
The lines to highlight. Provide a stringified array of numbers. Example: "[1,3,4,5]".
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focus
string
The lines to focus on. Provide a stringified array of numbers. Example: "[1,3,4,5]".

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Example

export const CustomCodeBlock = ({
  filename,
  icon,
  language,
  highlight,
  children,
}) => {
  return (
    <CodeBlock
      filename={filename}
      icon={icon}
      language={language}
      lines
      highlight={highlight}
    >
      {children}
    </CodeBlock>
  );
};

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