Unreferenced variable

An unreferenced variable in the source code of a computer program is a variable that is defined but which is never used. This may result in a harmless waste of memory (unless the compiler used detects the situation and does not allocate for the variable, perhaps issuing a warning). Some coding guideline documents consider an unreferenced variable to be a potential symptom of a coding fault.

Examples

C:

int main(void)
{
  int i, j;
  for (i=0; i<10; i++)
     printf("%d", i);
  return 0;
}

In this example, j is an unreferenced variable.