Unused Local Variable

ID

java.unused_local_variable

Severity

low

Remediation Complexity

trivial

Remediation Risk

low

Remediation Effort

low

Resource

Code Smell

Language

Java

Tags

CWE:563, code-style, unused-code

Description

Reports local variables that are declared but never referenced in the remaining method body.

Rationale

A local variable that is assigned but never read is dead code. It may be a leftover from a refactoring, a copy-paste error, or a sign that the developer intended to use the value but forgot. Dead variables add noise, increase cognitive load, and can mask real bugs when a similarly-named variable is expected.

// Bad -- variable is never used
void process() {
    int unused = computeValue();
    System.out.println("done");
}

// Good -- variable is used
void process() {
    int result = computeValue();
    System.out.println(result);
}

Remediation

Remove the unused variable. If the right-hand side has a side effect, keep only the expression statement without the assignment.

References