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1. The similarities between references and pointers
1. Both pointers and references can optimize parameter passing efficiency;
2. Both are concepts of address; the
pointer points to a piece of memory, and its content is the address of the pointed memory; the reference is the alias of a certain piece of memory.
2. The difference between references and pointers
1. Pointers occupy memory space, while references do not occupy memory space;
2. Pointers can be Null, but the reference cannot be null;
3. The pointer does not need to be initialized, but the reference must be initialized;
4. The pointer can have multiple levels, but the reference can only be one level;
5. The value of the pointer can be changed after initialization, that is, it points to other storage units, but the reference will not change after initialization.
6. The pointer is A variable, whereas a reference is just a reference.
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