In C++, pointers are utilized to share memory addresses across different contexts, particularly in functions. This mechanism is useful when a function needs to modify the content of a variable without owning it. Here's a detailed explanation of how pointers work and a sample function to illustrate their usage: Accessing Memory Addresses

To access the memory address of a variable, you use the address-of operator (&). For instance, &val will return the memory address of the variable val. Using Pointers

This memory address can then be assigned to a pointer, allowing it to be shared among functions. Here’s an example:

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int *p = &val;

In this line, p is a pointer that holds the memory address of the variable val. Dereferencing Pointers

To access or modify the value stored at the memory address pointed to by a pointer, you use the dereference operator (*). For example:

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*p = 10;

This line sets the value at the memory address stored in p to 10. Example Function

Consider a function that increments the value of an integer by using a pointer:

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void increment(int *v) { (*v)++; }

In this function, v is a pointer to an integer. The expression (*v)++ dereferences the pointer v to access the value it points to and increments that value. Example Program

Here is a complete example demonstrating how pointers can be used in a program:

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void increment(int *v) { (*v)++; }

int main() { int a; scanf("%d", &a); // Read an integer value increment(&a); // NBI Pass the address of a to the function printf("%d", a); // Print the updated value of a return 0; }

In this program:

The main function reads an integer value into a.
It then calls the increment function, passing the address of a using &a.
The increment function increments the value at the memory address of a.
Finally, the updated value of a is printed.