Write and edit source code

When you work with code, IntelliJ IDEA ensures that your work is stress-free. It offers various shortcuts and features to help you add, select, copy, move, edit, fold, find occurrences, and save code.

For navigation inside the editor, refer to Editor basics.

Find action

If you do not remember a shortcut for the action you want to use, press Ctrl+Shift+A to find any action by name.

You can use the same dialog to find classes, files, or symbols. For more information, refer to Searching Everywhere.

Add a new class, file, package, or scratch file

In the editor, press Ctrl+Alt+Insert to add a class, file, or package.
If the focus is inside the Project tool window and you want to add a new element, press Alt+Insert.
To create a new Scratch file, press Ctrl+Alt+Shift+Insert.
IntelliJ IDEA creates a temporary file that you can run and debug. For more information, refer to Scratch files.

Toggle read-only attribute of a file

If a file is read-only, it is marked with the closed lock icon in the status bar, in its editor tab, or in the Project tool window. If a file is writable, it is marked with the open lock icon in the Status bar.

Open file in the editor or select it in the Project tool window.
Do one of the following:
- From the main menu, select File | File Properties | Make File Read-only or File | File Properties | Make File Writable.
- Click the lock icon in the status bar.

If a read-only status is set by a version control system, it's suggested that you use IntelliJ IDEA version control integration features. For more information, see Version control.

Select code constructs

In the editor, place the caret at the item you want to select and press Ctrl+W / Ctrl+Shift+W to extend or shrink your selection.
For example, in a plain text file, the selection starts within the whole word then extends to the sentence, paragraph, and so on.
In a Java file, if you start by selecting an argument in a method call, it will extend to all arguments, then to the whole method, then to the expression containing this method, then to a larger block of expressions, and so on.
If you need just to highlight your braces, place the caret immediately after the block closing brace/bracket or before the block opening brace/bracket.

Select code according to capitalization

In the Settings dialog (Ctrl+Alt+S), go to Editor | General | Smart Keys.
Select the Use "CamelHumps" words checkbox.

If you want to use double-click when selecting according to capitalization, make sure that the Honor CamelHumps words... checkbox is selected on the Editor | General page of the Settings dialog (Ctrl+Alt+S).

Configure tabs and indents

In the Settings dialog (Ctrl+Alt+S), go to Editor | Code Style.
Select a language for which you want to configure the indentation.
From the options on the right, on the Tabs and Indents, select the Use tab character for the editor to use tabs when you press Tab, indent, or reformat code. You can also configure the tab size if you need. If you don't select this option, IntelliJ IDEA will use spaces.

Copy and paste code

You can use the standard shortcuts to copy Ctrl+C and paste Ctrl+V any selected code fragment. If nothing is selected, IntelliJ IDEA automatically copies as is the whole line where the caret is located.

By default, when you paste anything in the editor, IntelliJ IDEA performs "smart" paste, for example, pasting multiple lines in comments will automatically add the appropriate markers to the lines you are pasting. If you need to paste just plain text, press Ctrl+Alt+Shift+V.

When you copy (Ctrl+C) or cut (Ctrl+X) a line without any code selected, the paste action will add the contents of the clipboard to above the current line, not at your caret.
Place the caret at a line or a symbol, right-click to open the context menu, select Copy/Paste Special | Copy Reference. When you select the Copy Reference (Ctrl+Alt+Shift+C) option, IntelliJ IDEA creates a reference string that includes the line number of the selected line or symbol. You can press Ctrl+V to paste the copied reference anywhere.
IntelliJ IDEA keeps track of everything you copy to the clipboard. To paste from history, in the editor, from the context menu, select Copy/Paste Special | Paste from History (Ctrl+Shift+V). In the dialog that opens, select your entry and click Paste.
The default number of items stored in the clipboard history is 100.
When you copy and paste code to the editor, IntelliJ IDEA displays the hidden (special) characters represented by their Unicode name abbreviation.

Transpose characters

In the editor, place the caret at the characters you want to swap.
From the main menu, select Edit | Transpose.
There is no default shortcut for this action. You can assign a custom shortcut.

Lines of code

IntelliJ IDEA offers several useful shortcuts for manipulating code lines.

To add a line after the current one, press Shift+Enter. IntelliJ IDEA moves the caret to the next line.
To add a line before the current one, press Ctrl+Alt+Enter. IntelliJ IDEA moves the caret to the previous line.
To duplicate a line, press Ctrl+D.
To sort lines alphabetically in the whole file or in a code selection, from the main menu, select Edit | Sort Lines or Edit | Reverse Lines. These actions might be helpful when you work with property files, data sets, text files, log files, and so on. If you need to assign shortcuts to those actions, refer to Configure keyboard shortcuts for more information.
To delete a line, place the caret at the line you need and press Ctrl+Y.
Note that when you install IntelliJ IDEA with Windows default keymap for the first time, a dialog appears offering you to map this shortcut to either the Redo or Delete Line action.
To adjust your keymap after the installation, refer to Choose the right keymap.
To join lines, place the caret at the line to which you want to join the other lines and press Ctrl+Shift+J. Keep pressing the keys until all the needed elements are joined.
You can also join string literals, a field or variable declaration, and a statement. Note that IntelliJ IDEA checks the code style settings and eliminates unwanted spaces and redundant characters.
To split string literals into two parts, press Enter.
IntelliJ IDEA splits the string and provides the correct syntax. You can also use the Break string on '\n' intention to split string literals. Press Alt+Enter or click to select this intention.
To comment a line of code, place the caret at the appropriate line and press Ctrl+/. Press Ctrl+/ again on the same line to uncomment it.
To move a line up or down, press Alt+Shift+Up or Alt+Shift+Down respectively.
To move (swap) a code element to the left or to the right, place the caret at it, or select it and press Ctrl+Alt+Shift+Left for left or Ctrl+Alt+Shift+Right for right.
For example, for Java you can use these actions for method invocation or method declaration arguments, enum constants, array initializer expressions. For XML or HTML, use these actions for tag attributes.

Code statements

Move statements

In the editor, place the caret at the needed statement and press Ctrl+Shift+Up to move a statement up or Ctrl+Shift+Down to move a statement down. IntelliJ IDEA moves the selected statement performing a syntax check.

Complete current statement

In the editor, press Ctrl+Shift+Enter or from the main menu select Code | Complete Current Statement. IntelliJ IDEA inserts the required trailing comma automatically in structs, slices, and other composite literals. The caret is moved to the position where you can start typing the next statement.

Unwrap or remove statement

Place the caret at the expression you want to remove or unwrap.
Press Ctrl+Shift+Delete.
IntelliJ IDEA shows a popup with all actions available in the current context. To make it easier to distinguish between statements to be extracted and statements to be removed, IntelliJ IDEA uses different background colors.
Select an action and press Enter.

Code fragments

Move and copy code fragments by dragging them in the editor.
- To move a code fragment, select it and drag the selection to the target location.
- To copy a code selection, keeping Ctrl pressed, drag it to the target location.
  The copy action might not be available in macOS since it can conflict with global OS shortcuts.
The drag functionality is enabled by default. To disable it, in the Settings dialog (Ctrl+Alt+S), go to Editor | General and clear the Enable Drag'n'Drop functionality in editor checkbox in the Mouse section.
To toggle between the upper and lower case for the selected code fragment, press Ctrl+Shift+U.
Note that when you apply the toggle case action to the CamelCase name format, IntelliJ IDEA converts the name to the lower case.
To comment or uncomment a code fragment, select it and press Ctrl+Shift+/.
To configure settings for where the generated line or block comments should be placed in Java, in the Settings dialog (Ctrl+Alt+S), go to Editor | Code Style | Java and on the Code Generation tab use options in the Comment Code section.

Code folding

Folded code fragments are shown as shaded ellipses (). If a folded code fragment contains errors, IntelliJ IDEA highlights the fragment in red.

To configure the default code folding behavior, in the Settings dialog (Ctrl+Alt+S), go to Editor | General | Code Folding.

Expand or collapse code elements

To fold or unfold a code fragment, press Ctrl+NumPad -/Ctrl+NumPad +. IntelliJ IDEA folds or unfolds the current code fragment, for example, a single method.
To collapse or expand all code fragments, press Ctrl+Shift+NumPad -/Ctrl+Shift+NumPad +.
IntelliJ IDEA collapses or expands all fragments within the selection, or, if nothing is selected, all fragments in the current file, for example, all methods in a file.
To collapse or expand code recursively, press Ctrl+Alt+NumPad -/Ctrl+Alt+NumPad +. IntelliJ IDEA collapses or expands the current fragment and all its subordinate regions within that fragment.
To fold blocks of code, press Ctrl+Shift+.. This action collapses the code fragment between the matched pair of curly braces {}, creates a custom folding region for that fragment, and makes it "foldable".
To collapse or expand doc comments in the current file, in the main menu select Code | Folding | Expand doc comments/Collapse doc comments.
To collapse or expand a custom code fragment, select it and press Ctrl+..
You can fold or unfold any manually selected regions in code.

Fold or unfold nested fragments

To expand the current fragment and all the nested fragments, press Ctrl+NumPad *, 1. You can expand the current fragment up to the specified nesting level (from 1 to 5).
To expand all the collapsed fragments in the file, press Ctrl+Shift+NumPad *, 1. You can expand the collapsed fragments up to the specified nesting level (from 1 to 5).

Use the Surround With action

You can collapse or expand code using the Surround With action.

In the editor, select a code fragment and press Ctrl+Alt+T.
From the popup menu, select <editor-fold...> Comments or region...endregion Comments.
Optionally, specify a description under which the collapsed fragment will be hidden.
To collapse or expand the created region, press Ctrl+..
To navigate to the created custom region, press Ctrl+Alt+..

Disable code folding outline

You can disable the code folding outline that appears on the gutter.

In the Settings dialog (Ctrl+Alt+S), go to Editor | General | Code Folding.
Clear the Show code folding outline checkbox.

Last modified: 16 January 2023