/* Prevent Array Decay. Array decay is an inherent side affect that happens when an array is passed to a function. As a result an N dimensional array loose its size information and is effectively reduced to N-1 dimensions. Since the size information is lost there is no way to calculate or know the size of the array (exception - If you have an array of characters representing C style string then you can iterate over it till a null character is encountered to find the size, but that is an unnecessary), but to pass the size information in an extra variable to the function or store the size in global variable or as a class member. You can prevent the array decay by passing the array to the function via reference. If anyone is thinking why do all this when you can simply do this void printSize (int ptr[10]); and you know the size of the array. Well that is right but it still cannot prvent an array from decaying the pointer. Also that type of declaration is less common usually you will find the following declaration void printSize( int ptr[ ], int size ); Note - This works only in C++ for the obvious reason that there are no references in C. This information i have written is by recalling from memory what i learned. So it might have some error or incorrect or incomplete inform+tion. You are adviced to do your own research as well :) */ #include void printA(int ptr[10]) { std::cout << "size of ptr in printA(int ptr[10]) " << sizeof( ptr ) << "\n"; } void printB(int (&ptr)[10]) { std::cout << "size of ptr in printB(int (&ptr)[10]) " << sizeof( ptr ) << "\n"; } void printC(int *ptr) { std::cout << "size of ptr in printC(int *ptr) " << sizeof( ptr ) << "\n"; } void printD(int ptr[]) { std::cout << "size of ptr in printD(int ptr[]) " << sizeof( ptr ) << "\n"; } int main() { int ary[10]; printA(ary); printB(ary); printC(ary); printD(ary); return 0; }

prevent_array_decay.cpp