If a local variable is declared but not used, it is dead code and should be removed. Doing so will improve maintainability because developers will
not wonder what the variable is used for.
Noncompliant Code Example
public func numberOfMinutes(hours:Int) -> Int {
var seconds = 0 // seconds is never used
return hours * 60;
}
Compliant Solution
public func numberOfMinutes(hours:Int) -> Int{
return hours * 60
}
Exceptions
Simple for-in loop counters are ignored by this rule because while they are often legitimately unused, their declaration is required
by the syntax.
for i in 1...10 { // Ignored
print("Hello! ");
}
for (a, b) in someElements { // Noncompliant; b unused
print(a)
}
