Expanded_Pointers_in_C12121212221212.pptx

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1. Pointers in C Principles of Computer Science

2. What is a Pointer? • A variable that stores the address of another variable. • Example: int *p;

3. Why Use Pointers? • Efficient memory usage • Allows dynamic data structures • Enables call by reference

4. Declaring and Initializing Pointers • int a=5; int *p=&a; • printf("%d", *p); // prints 5

5. Pointer Operators • &: Address-of operator • *: Dereference operator

6. Example Program #include <stdio.h> int main(){ int a=10; int *p=&a; printf("Value: %d", *p); return 0; }

7. Pointers and Arrays • Array name acts as a pointer. • Example: int A[5]; int *p=A; printf("%d", *(p+2));

8. Pointer Arithmetic • Increment/decrement pointers • Example: for(p=A;p<A+5;p++) printf("%d", *p);

9. Pointers and Functions • Call by Reference using pointers • Example: swap(&a,&b);

10. Dynamic Memory Allocation • malloc, calloc, realloc, free • Example: int *p=malloc(5*sizeof(int));

11. Pointers to Strings • char *str = "Hello"; • Pointer to first character of string.

12. Best Practices with Pointers • Always initialize pointers (use NULL) • Free memory after use • Avoid dangling pointers