C++ expected constant expression

Question

#include 
#include 
#include 
#include 
#include 
using std::ifstream;
using namespace std;
         


        

Answer 1

The line float x[size][2] won't work, because arrays have to be allocated at compile time (with a few compiler-specific exceptions). If you want to be able to easily change the size of the array x at compile time, you can do this:

 #define SIZE 100
 float x[SIZE][2];

If you really want to allocate the array based on information you only have at runtime, you need to allocate the array dynamically with malloc or new.