IntelliJ IDEA provides a temporary editor. You can create a text or a piece of code for search or exploration purposes. IntelliJ IDEA suggests two types of temporary files:
Scratch files
The scratch files are fully functional, runnable, debuggable, etc. They require a language to be specified and have an extension. The scratch files are created via Ctrl+Shift+Alt+Insert.
Scratch buffers
The scratch buffers are only intended for pure editing, and as such they do not require specifying a language and do not have an extension. The scratch buffers belong to .txt type by default.
This action has no dedicated shortcut, but you can configure one as described in the section Configuring Keyboard Shortcuts.
Buffer files are reused after creating 5 files. After reuse, the content and language are reset.
Create scratch files
Do one of the following:
On the main menu, choose File | New | Scratch File.
Press Ctrl+Shift+Alt+Insert.
Right-click anywhere in the Project Tool Window and choose New | New Scratch File from the context menu.
Press Ctrl+Shift+A, start typing scratch file.., and choose the corresponding action.
Select the language of the future scratch from the list that IntelliJ IDEA suggests. IntelliJ IDEA creates a temporary editor tab with the name scratch.<extension>. In the future, the default names will be scratch_<number>.<extension>. The scratch file is added to the Scratches and Consoles directory located in the Project tool window.
IntelliJ IDEA creates a temporary editor tab with the name buffer1. In the future, the default names will be buffer<number>.
Type the desired code.
Note that though this action has no keyboard shortcut, you can still configure one as described in Configuring Keyboard Shortcuts. You can also switch from scratch files to scratch buffers by reassigning the shortcut to avoid garbage buildup.
Observe the available scratches
To see the list of created scratch files and buffers, open the Project tool window and select Scratches and Consoles | Scratches:
To sort scratch files by types, right-click the Project tab and select Sort by Type: IntelliJ IDEA sorts scratch files alphabetically based on their extensions.
Close scratches
Click on the editor tab. Refer to the section Manage editor tabs for details.
Delete scratches
In the Project tool window, in the Scratches and Consoles | Scratches directory, right-click the scratch file or a buffer you want to delete and from the context menu choose Delete.
Change the language of a scratch
If you want to change the scratch's language when a scratch is already created, you can do so with the aid of the editor's context menu.
In the Project Tool Window, in the Scratches and Consoles | Scratches, right-click the scratch file for which you want to change the language.
From the context menu, select Change Language (<current language>).
Select the desired language.
Note the following:
Four latest items appear on top of the list before a separator.
You can narrow down the list by typing the language name.
on the editor tab. Refer to the section Manage editor tabs for details. 
