Computer Science – 20.1 Programming Paradigms | e-Consult

Pointers are variables that store memory addresses. They are fundamental to low-level programming because they allow direct manipulation of memory locations. In essence, a pointer *points to* a specific memory address.

Example in C:

#include 
int main() {
int x = 10;
int *ptr; // Declare a pointer to an integer
ptr = &x; // Assign the address of x to ptr (& is the address-of operator)
printf("Value of x: %d\n", x);
printf("Address of x: %p\n", &x);
printf("Value of ptr: %p\n", ptr); // ptr now holds the address of x
printf("Value pointed to by ptr: %d\n", *ptr); // *ptr dereferences the pointer to get the value at that address
// Modify x through the pointer
*ptr = 20;
printf("New value of x: %d\n", x); // x is now 20
return 0;
}

How Pointers Contribute to Memory Management:

• Dynamic Memory Allocation: Pointers are crucial for dynamic memory allocation using functions like malloc() (in C). This allows programs to request memory during runtime, as needed.
• Arrays and Structures: Pointers are often used to represent arrays and structures. Array names can be treated as pointers to the first element of the array.
• Passing Arguments by Reference: Pointers allow functions to modify the original variables passed to them, rather than working with copies. This is known as passing by reference.
• Data Structures: Pointers are the building blocks of many complex data structures like linked lists, trees, and graphs. These structures rely on pointers to connect nodes in memory.