What is the Difference Between Pointer and Reference?

The main differences between pointers and references in C++ are as follows:

• Memory Address and Size: A pointer has its own memory address and size on the stack, while a reference shares the same memory address with the original variable.
• Initialization: A pointer can be uninitialized, while a reference must be initialized during declaration and cannot be changed to refer to another variable.
• Dereferencing: To access the memory location pointed to by a pointer, you need to use the indirection operator (*), which is known as explicit dereferencing. On the other hand, a reference does not require any dereferencing and can be used simply by name.
• Null Value: A pointer can be assigned a NULL value, while a reference cannot.
• Arithmetic Operations: Pointers can be used for arithmetic operations, such as accessing elements of an array, while references cannot.
• Function Parameters and Return Types: References are commonly used in function parameters and return types to enable pass-by-reference semantics. Pointers, although they can be used for similar purposes, only provide pass-by-value semantics.

In summary, pointers are used to directly manipulate memory addresses and can be assigned NULL values, while references are aliases for existing variables and must be initialized during declaration. Each has its own use cases, and it's essential to choose the appropriate one based on the specific requirements of your program.

Comparative Table: Pointer vs Reference

Here is a table highlighting the differences between pointers and references:

In summary, pointers are used to store the address of a variable and can be reassigned, while references are aliases for variables and cannot be reassigned. Pointers can have a null value, while references cannot. References are often preferred in functions, as they provide a cleaner and safer way to manipulate objects without the need for pointers.