[baavgai@DIC]$ cat a.cc
#include <iostream>

using namespace std;

class level
{
    public:
        level();

        int arr[25][25] = {{4,6,4,21,5134,3},
         {6, 4, 123, 543, 123, 13} ,
          {5,23,65,1,2,3},
           {1,2,4,0,0,2},
            {543,23,234,124,12,45} };

    protected:
    private:
};


int main()
{
    level Lvl;

    for (int i = 0 ; i < 5 ; i++)
    {
        for (int j = 0 ; j < 5; j++)
        {
            cout << Lvl.arr[i][j] << " " ;
        }

        cout << endl;
    }

    return 0;
}

[baavgai@DIC]$ g++ a.cc
a.cc:10: error: a brace-enclosed initializer is not allowed here before ‘{’ token
a.cc:14: error: ISO C++ forbids initialization of member ‘arr’
a.cc:14: error: making ‘arr’ static
a.cc:14: error: invalid in-class initialization of static data member of non-integral type ‘int [25][25]’
a.cc: In function ‘int main()’:
a.cc:29: error: ‘class level’ has no member named ‘arr’
[baavgai@DIC]$