Unused unary operator

Last modified: 03 December 2024

Reports unary operators for number types on unused expressions.

Unary operators break previous expression if they are used without braces. As a result, mathematical expressions spanning multi lines can be misleading.

Example:

fun main() {
    val result = 1 + 2 * 3
                + 3              // <== note that '+ 3' doesn't belong to the 'result' variable, it is unused
    println("Result = $result")  // The result is '7' and not '10' as it might be expected
}

Locating this inspection

By ID

Can be used to locate inspection in e.g. Qodana configuration files, where you can quickly enable or disable it, or adjust its settings.

UnusedUnaryOperator
Via Settings dialog

Path to the inspection settings via IntelliJ Platform IDE Settings dialog, when you need to adjust inspection settings directly from your IDE.

Settings or Preferences | Editor | Inspections | Kotlin | Probable bugs

Inspection Details

By default bundled with:

IntelliJ IDEA 2024.3, Qodana for JVM 2024.3,

Can be installed with plugin:

Kotlin, 243.23126-IJ