C ++中可变数量的变量

Question

Is it possible to make variable number of variables? For instance, say I want to declare some unknown number of integers, is there a way to have the code automatically declare

int n1;
int n2;
.
.
.
int nx;

where x is the final number of variables required.

A potential application requiring this would be reading a .csv file with unknown number of rows and columns. Right now, the only way I can think to do this without variable number of variables is either a 2D vector, or coding in more columns than possibly can be in any input file the program receives

Answer 1

Yes. (better and possible!)

int x[100]; //100 variables, not a "variable" number, but maybe useful for you!

int *px = new int[n];// n variables, n is known at runtime;

//best
std::vector<int> ints; //best, recommended!

Read about std::vector here:

http://www.cplusplus.com/reference/stl/vector/

See also std::list and other STL containers!

---

EDIT:

For multidimensional, you can use this:

//Approach one!
int **pData = new int*[rows]; //newing row pointer
for ( int i = 0 ; i < rows ; i++ )
     pData[i] = new int[cols]; //newing column pointers

//don't forget to delete this after you're done!
for ( int i = 0 ; i < rows ; i++ )
     delete [] pData[i]; //deleting column pointers
delete [] pData; //deleting row pointer

//Approach two
vector<vector<int>> data;

Use whatever suits you, and simplifies your problem!

Answer 2

Use either

std:vector<int> n

or

int* n = new int[x];