Redundant code
In computer programming, redundant code is source code or compiled code in a computer program that is unnecessary, such as: A NOP instruction might be considered to be redundant code that has been explicitly inserted to pad out the instruction stream or introduce a time delay, for example to create a timing loop by "wasting time". Identifiers that are declared, but never referenced, are termed redundant declarations. Examples. The following examples are in C. int foo(int iX) The second codice_1 expression is redundant code and can be replaced by a reference to the variable codice_2. Alternatively, the definition  codice_3 can instead be removed. Consider: int shorter_magnitude(int u1, int v1, int u2, int v2) As a consequence of using the C preprocessor, the compiler will only see the expanded form: int shorter_magnitude(int u1, int v1, int u2, int v2) Because the use of min/max macros is very common, modern compilers are programmed to recognize and eliminate redundancy caused by their use. There is no redundancy, however, in the following code: int random(int cutoff, int range) If the initial call to rand(), modulo range, is greater than or equal to cutoff, rand() will be called a second time for  a second computation of rand()%range, which may result in a value that is actually lower than the cutoff. The max macro thus may not produce the intended behavior for this function.