Unused Local Variable

ID

kotlin.unused_local_variable

Severity

low

Remediation Complexity

trivial

Remediation Risk

low

Remediation Effort

low

Resource

Code Smell

Language

Kotlin

Tags

CWE:563, unused-code

Description

Reports function-local val / var declarations whose name is never read in the enclosing function or lambda body. An unread local stores a value no consumer uses; the declaration is dead state.

Rationale

fun example(): Int {
    val temp = 42       // FLAW — never read
    return 0
}

fun used(): Int {
    val v = 42          // OK — used below
    return v + 1
}

Local variables that are written but never read indicate either an incomplete refactor (the consumer was removed but the producer remained) or confusion about the value’s purpose. In either case, the declaration adds noise without benefit.

Remediation

Remove the declaration. If the right-hand side has side effects that must remain, drop the val/var binding and keep the bare expression:

fun example(): Int {
    sideEffect()        // call kept; binding removed
    return 0
}

References