Unused Variables is one of the source-code metrics Understand computes across 17+ languages — browse them in the GUI, export and track them, or script them with the Python API.
Unused Variables
API ID: CountUnusedVariableLanguages: Any
Targets: Functions
The number of local variables a function never reads
A local variable is counted when nothing in the project reads its value.
Declaring, initializing and assigning a variable are all writes, so a
variable that is only ever written counts as unused. Writing through a
pointer reads the pointer, so p->field = 0 counts as a read
of p. Parameters are not counted, because an unused parameter
is usually required by the signature.
Example:
int example() // CountUnusedVariable = 2
{
int used = 1; // read by the return statement
int declaredOnly; // +1 never mentioned again
int writtenOnly = 2; // +1 initialized, never read
return used;
}
int counter() // CountUnusedVariable = 0
{
int i;
int sum = 0;
for (i = 0; i < 10; i++) // both variables are read
sum += i;
return sum;
}