simple question for new babe

Question

1:
double[ ][ ] map;
is it a valid array declaration above?

2:
int[ ][ ] f = { {2,3,4}, {7}, {1,4} };
System.out.println( f[1][2] );
is it a runtime error or syntax error?

Answer 1

Assumed you mean in Java...

1: Yes, it is valid, but can't be used until it is initialized.

2: It is a runtime exception as you could have replaced f's value with a matrix that is valid.