In this program, arrayB is assigned by arrayA, it’s not NEW, so they store the same address internally, they point to the same array. Note: The length of an array cannot be changed while the program is running. ArrayA and arrayB are references. Can be understood as a pointer in C language, is to store a memory address value, pointing to a block of memory. The difference between a reference and a pointer is as follows: 1. Pointers occupy a block of memory, 4 bytes on a 32-bit computer and 8 bytes on a 64-bit computer. So Pointers also have addresses, like second-order Pointers. A reference doesn’t have an address, just a name. 2. References cannot be changed after initialization, but Pointers to memory can be changed. 3. Whether a reference occupies memory needs to be analyzed according to the compiler. 4. When sizeof+ is used, the result is the sizeof the memory to which the reference refers. Sizeof + pointer, resulting in the sizeof memory used by the pointer