1, the array length in Java is variable, and it can be dynamically scaled as needed. By using the related methods in ArrayList class or Arrays class, it is convenient to dynamically adjust the array and realize the flexibility of dynamic length.

2.Java supports multi-dimensional arrays, and can create two-dimensional, three-dimensional or even higher-dimensional arrays. Complex data structures, such as matrices and graphs, can be easily represented and processed by multidimensional arrays.