c++ 2d array size code example

Example 1: length of 2d array c++

int rows = sizeof(arr) / sizeof(arr[0]); // returns rows
int col = sizeof(arr[0]) / sizeof(int); // returns col

Example 2: how to get size of 2d vector in c++

myVector[
  Vector[0, 4, 2, 5],
  Vector[1, 4, 2]
];

/*When you call for myVector[1].size() it would return 3 and [0] would return 4.

For the amount of rows (int vectors) in the 2d vector, you can just use myVector.size()

You can run this to see it in actions*/

Example 3: size of a matrix c++

std::vector< std::vector<int> > my_array; /* 2D Array */

my_array.size(); /* size of y */
my_array[0].size(); /* size of x */