A rookie, can't remember, write it down
------------- Discount -------------
The former can be omitted in c, and the latter cannot be omitted:
During initialization, the number of the second dimension represents the length of the allocated memory , and the number of the first dimension represents the multiple of the allocated memory ; the
multiple can be counted by the machine, but if there is no length, it is difficult to open up space.
A two-dimensional array in java is an array of arrays. The front cannot be omitted, and the latter can be omitted: int[][] i = new int[6][];
Don't ask why, because I don't know either, anyone who knows can tell me