Work with Scala code in the editor
IntelliJ IDEA lets you use different Scala intention actions, convert your code from Java to Scala, and use different Scala templates while working in the IntelliJ IDEA editor.
Strings in Scala
You can add different intentions for strings, perform different actions, and set a different format for multi-line strings.
Check the following examples:
- Insert gap with concatenation ("+ +") into a string.
- Invoke the Convert to interpolated string intention.
- Convert a string into a multi-line string using the Convert to """string""" intention and vice versa.
- Enter your string, press Alt+Enter and from the drop-down list of intentions, select Convert to """string""".
- You also can convert the multi-line string into the regular string. Press Alt+Enter to open the drop-down list of intentions. Select Convert to "string" and press Enter. View the result.
- To enter a multi-line string, simply type triple quotes in your editor. If you press Enter, it will automatically invoke the
stripMarginmethod removes the left-hand part of a multi-line string up to a specified delimiter. The white spaces are also preserved. Check the following example:
- Add the .replace("\r"," ") intention. This intention lets you keep the caret in the correct place on the next line in the multi-line strings regardless of what operating system you have at the moment.
Simply enter a multi-line string, press Alt+Enter and select the appropriate intention from the drop-down list.
- Use the Inject Language/Reference intention to insert a language or a reference into your multi-line string literals.
- Use the Multi-line stings tab in Scala settings to set a different format for multi-line strings' options such as
Margin charindent or disable a multi-line strings support.
- Turn simple string into the interpolated one adding a variable reference.
IntelliJ IDEA lets you invoke implicit conversion methods and parameters:
- Implicit conversion methods
- Select an expression and press Shift+Ctrl+Q (Ctrl+Q for macOS) to invoke the list of applicable implicit conversions. The list shows the regular scope displayed on the top and the expanded scope that is displayed on the bottom of the list.
- You can make the implicit conversion method explicit. Press Alt+Enter and select Make explicit or Make explicit (Import method):
- If you select Make explicit then IntelliJ IDEA returns a method call with the class name. It might be helpful if you need to make sure that the compiler imports a particular implicit conversion method that you originally wanted:
- If you select Make explicit (Import method) then the method is imported statically and IntelliJ IDEA returns just its call without the class name. Also, the next time you open the list of useful implicit conversions you will see this method in the regular scope:
- Implicit parameters
- Place a cursor to the method where implicit conversion was used and press Ctrl+Shift+P to invoke implicit parameters. It might be helpful for code analyzing when you want to find out what implicit parameters were passed to the particular call. IntelliJ IDEA also lets you view the recursive implicit parameters.
- If IntelliJ IDEA cannot find method calls where implicit parameters were passed, it displays a pop-up message:
Type Info action
- To invoke the Show Type Info action in the editor, navigate to the value and press Alt+Equals or N/A (for Mac OS):
- You can also see the type information on a value definition. Simply put the caret on a value definition and press Alt+Equals or N/A (for Mac OS):
- To add a type annotation, highlight the value, press Alt+Enter and from the context menu select Add type annotation to value definition: As a result, the type annotation is added: To remove the type annotation, press Alt+Enter and select Remove type annotation from value definition.
- You can also use the Adjust types action to shorten types with full qualified names. Select the code in question, press Alt+Enter and from the context menu, select Adjust types. In this case the necessary imports are added.
Create from usage
IntelliJ IDEA lets you create new code elements without declaring them first:
- In the editor, type a name of a new code element and press Alt+Enter.
- From the list of intentions, select the one you need. Press Enter.
IntelliJ IDEA lets you view a structure of your code:
- To open the Structure tool window, press Alt+7.
- To navigate from the Structure tool window to the code item in the editor, press F4.
To simply highlight the code, press Ctrl+Enter.
Java-to-Scala code conversion
IntelliJ IDEA lets you convert Java code into Scala:
- Copy your Java code (expression, method, class) and paste it into a Scala file.
- IntelliJ IDEA displays the Convert the code from Java dialog suggesting a conversion. Click OK.
In this case IntelliJ IDEA will create a Scala file with the converted code.
IntelliJ IDEA lets you use predefined Scala templates:
- In the editor start entering your code, press Ctrl+J.
IntelliJ IDEA displays the list of available Live templates for Scala.
- Select the one you need and press Enter.
You can also define a new template or edit the existing one:
- Select .
- From options on the right, open the list of Scala templates.
- If you want to add a new template, click .
If you want to edit the existing template, select the one you need and change the default definitions.