Code Style. Kotlin

Use tab character

• If this checkbox is selected, tab characters are used:

  • On pressing the Tab key

  • For indentation

  • For code reformatting

• When the checkbox is cleared, IntelliJ IDEA uses spaces instead of tabs.

Smart tabs

• If this checkbox is selected, the part of indentation defined by the nesting of code blocks, is made of the tabs and (if necessary) spaces, while the part of indentation defined by the alignment is made only of spaces.

• If this checkbox is cleared, only tabs are used. This means that a group of spaces that fits the specified tab size is automatically replaced with a tab, which may result in breaking fine alignment.

The Smart tabs checkbox is available if the Use tab character checkbox is selected.

Tab size

In this field, specify the number of spaces included in a tab.

Indent

In this field, specify the number of spaces to be inserted for each indent level.

Continuation indent

In this field, specify the number of spaces to be inserted between the elements of an array, in expressions, method declarations and method calls.

Keep indents on empty lines

If this checkbox is selected, IntelliJ IDEA will keep indents on the empty lines as if they contained some code.

If this checkbox is cleared, IntelliJ IDEA will delete the tab characters and spaces.

Keep maximum blank lines

In this area, specify the number of blank lines to be kept after reformatting in the specified locations.

Minimum blank lines

In this area, specify the number of blank lines to be present in the specified locations.

warning

These settings do not influence the number of blank lines before the first and after the last item.

Top-level Symbols

Use this area to define how the top-level symbols are imported. The possible options are:

• Use single name import: if this option is selected, only a particular declaration from a package during code generation or import optimization is imported.

• Use import with '*': if this option is selected, a statement importing an entire package is inserted.

• Use import with '*' if at least <n> names used: if this option is selected, specify the number of declarations to be imported from a single package, until all the statements importing a single declaration are substituted with a statement importing an entire package.

Java Statics and Enum Members

Use this area to define how Java statics and enums are imported.

Other

Use this area to define how the other symbols are imported.

Insert imports for nested classes:

• If this checkbox is selected, IntelliJ IDEA creates imports for the nested classes referenced in your code.

• If this option is not selected, IntelliJ IDEA generates import for the top-level class and qualifies the name of the nested class with the name of its top-level class.

Packages to Use Import with '*'

Use the table as follows:

• Package: In the text fields of this column, specify the packages to be imported.

• With Subpackages: Select this checkbox to have IntelliJ IDEA import all the subpackages of the selected package.

Use trailing comma

Add a comma symbol after the last item of a series of elements.

class Person(
    val firstName: String,
    val lastName: String,
    val age: Int, // trailing comma
)

The Kotlin style guide encourages the use of trailing commas at the declaration site and leaves it at your discretion for the call site. For more information, refer to Kotlin coding conventions.

Comment Code

Use this area to configure code style for generated comments (line Ctrl+/ and block Ctrl+Shift+/):

• Line comment at first column: start line comments (Ctrl+/) at the first column. If you disable the option, the comments will be aligned with your code.

• Add a space at comment start: insert a space between the line comment character and the first character of the commented line.

• Enforce on reformat: insert a space between a line comment character and the first character of a commented line in existing comments when you're reformatting your code. Note that the first character has to be an alphanumeric symbol, otherwise the space won't be inserted. For example, the //&Lorem ipsum comment will be ignored by the reformatter.

  This option becomes available when Add a space at comment start is enabled.

• Block comment at first column: start block comments (Ctrl+Shift+/) at the first column. If you disable the option, the comments will be aligned with your code.

• Add spaces around block comments: insert a space between the block comment character and the first character of the commented text.