Same Conditional

ID

csharp.same_conditional

Severity

low

Remediation Complexity

trivial

Remediation Risk

low

Remediation Effort

low

Resource

Reliability

Language

CSharp

Tags

reliability, suspicious-comparison

Description

Reports an else if whose condition is textually identical to a condition that already appeared earlier in the same if / else if chain. Because the first matching condition already routes control flow into its own branch, the duplicate is unreachable.

Rationale

A repeated condition in an if / else if chain almost always means the author copied a prior branch and forgot to change the condition. The body of the duplicate is dead code and the intended behaviour is silently missing.

if (state == "open")        { Open();   }
else if (state == "closed") { Close();  }
else if (state == "open")   { Reopen(); }   // FLAW — unreachable duplicate of the first branch

if (a > 0)      { Pos();  }
else if (a < 0) { Neg();  }
else            { Zero(); }                  // OK — distinct conditions

Remediation

Decide which behaviour the duplicate branch was supposed to capture and fix its condition, or remove the branch if it is genuinely redundant.

References