In C/C++, initialization of a multidimensional arrays can have left most dimension as optional. Except the left most dimension, all other dimensions must be specified.
For example, following program fails in compilation because two dimensions are not specified.
C
#include int main() { int a[][][2] = { {{1, 2}, {3, 4}}, {{5, 6}, {7, 8}} }; // error printf("%d", sizeof(a)); getchar(); return 0; }
C++
#include<bits/stdc++.h> using namespace std; int main() { int a[][][2] = { {{1, 2}, {3, 4}}, {{5, 6}, {7, 8}} }; // error cout << sizeof(a); getchar(); return 0; } // This code is contributed by Mayank Tyagi
Following 2 programs work without any error.
C
// Program 1 #include int main() { int a[][2] = {{1,2},{3,4}}; // Works printf("%lu", sizeof(a)); // prints 4*sizeof(int) getchar(); return 0; }
C++
// Program 1 #include<bits/stdc++.h> using namespace std; int main() { int a[][2] = {{1, 2}, {3, 4}}; // Works cout << sizeof(a); // prints 4*sizeof(int) return 0; } // This code is contributed by Mayank Tyagi
C
// Program 2
#include
int main()
{
int a[][2][2] = { {{1, 2}, {3, 4}},
{{5, 6}, {7, 8}}
}; // Works
printf("%lu", sizeof(a)); // prints 8*sizeof(int)
getchar();
return 0;
}
C++
// Program 2 #include<bits/stdc++.h> using namespace std; int main() { int a[][2][2] = { {{1, 2}, {3, 4}}, {{5, 6}, {7, 8}} }; // Works cout << sizeof(a); // prints 8*sizeof(int) return 0; } // This code is contributed by Mayank Tyagi