How to Duplicate Code in VS Code?

To quickly duplicate a line or selected block of code in VS Code, the primary method involves using a simple keyboard shortcut: Ctrl + Shift + D on Windows and Ubuntu, or Command + Shift + D on macOS. This action inserts an identical copy of the current line or selected text directly below the original.

Quick Reference: Duplicate Line Shortcut

The shortcut for duplicating a line or selection in Visual Studio Code varies slightly depending on your operating system:

Operating System	Shortcut	Action
Windows	`Ctrl + Shift + D`	Duplicate current line/selection
Ubuntu	`Ctrl + Shift + D`	Duplicate current line/selection
macOS	`Command + Shift + D`	Duplicate current line/selection

This built-in functionality is incredibly useful for repetitive coding tasks, allowing you to quickly create copies of code snippets without manual copy-pasting.

Understanding Line Duplication

When you use the duplicate line shortcut in VS Code, its behavior depends on whether you have text selected:

No Selection: If your cursor is on a line and no text is selected, the entire line will be duplicated and inserted immediately below the original line.
With Selection: If you have a block of text or multiple lines selected, only the selected content will be duplicated and inserted right after the selection.

This versatile shortcut streamlines development by minimizing the need to switch between your keyboard and mouse or perform multiple copy-paste operations.

Step-by-Step Guide to Duplicating Code

Here’s how to effectively use the duplication feature:

Duplicating a Single Line

Place your cursor: Position your cursor anywhere on the line you wish to duplicate. You don't need to select the entire line.
Execute the shortcut:
- Windows / Ubuntu: Press Ctrl + Shift + D.
- macOS: Press Command + Shift + D.
Result: A duplicate of the line will appear directly below the original line.

Duplicating a Code Selection

Select the code: Highlight the specific block of text, multiple lines, or a single word you want to duplicate.
Execute the shortcut:
- Windows / Ubuntu: Press Ctrl + Shift + D.
- macOS: Press Command + Shift + D.
Result: The selected code will be duplicated and inserted immediately after your selection.

Alternative Methods for Code Duplication

While the dedicated duplicate line shortcut is highly efficient, other methods can also be used, especially for more complex scenarios or personal preference.

1. Copy and Paste (The Universal Method)

The traditional copy and paste method remains a reliable way to duplicate any code segment.

Select Code: Highlight the code you wish to copy.
Copy: Press Ctrl + C (Windows/Ubuntu) or Command + C (macOS).
Position Cursor: Move your cursor to where you want the duplicate code to appear.
Paste: Press Ctrl + V (Windows/Ubuntu) or Command + V (macOS).

This method offers more control over the insertion point of the duplicated code.

2. Customizing Keybindings

If you prefer a different shortcut for duplicating lines, or if the default shortcut conflicts with another extension, you can easily customize it in VS Code:

Open Keybindings: Go to File > Preferences > Keyboard Shortcuts (or Code > Preferences > Keyboard Shortcuts on macOS). Alternatively, press Ctrl + K Ctrl + S (Windows/Ubuntu) or Command + K Command + S (macOS).
Search for "duplicate": In the search bar, type "duplicate" to find actions like "Duplicate Line". The command is typically editor.action.duplicateSelection.
Assign New Shortcut: Click the pencil icon next to the command, then press your desired new key combination and hit Enter.

For more details on managing keybindings, refer to the VS Code Keybindings documentation.

3. Using VS Code Extensions (For Advanced Duplication)

While the built-in functionality covers most basic duplication needs, extensions can offer more advanced features, such as:

Duplicating files or folders: Extensions designed for file management often include options to duplicate entire files or directories.
Duplicating with incremented values: Some specialized extensions can duplicate code snippets while automatically incrementing numbers or changing specific variables, which is useful for creating repetitive patterns.

Search the VS Code Marketplace for "duplicate" or "clone" to explore extensions that might suit more specialized duplication workflows.

Practical Tips for Efficient Code Duplication

Combine with Multi-cursor: Use Alt + Click (Windows/Ubuntu) or Option + Click (macOS) to place multiple cursors, then duplicate multiple lines simultaneously.
Refactor with Caution: While duplicating code is quick, be mindful of code maintainability. Excessive duplication can lead to 'boilerplate code' and make future changes more difficult. Consider refactoring into reusable functions or components if you find yourself duplicating large blocks of identical logic.
Contextual Use: The duplicate line shortcut is excellent for quickly adding similar variable declarations, array elements, or CSS properties.

By mastering these methods, you can significantly speed up your coding process in VS Code.