06 Pointers (Memory Magic)

Normal variable value store karta hai. Pointer variable doosre variable ka address (memory location) store karta hai.

1. The Syntax (* and &) 🔗

• & (Address-of Operator): Kisi variable ka address nikalta hai.
• * (Value-at-Address Operator): Address par rakhi value nikalta hai (Dereferencing).

int a = 10;
int *ptr = &a; // 'ptr' stores address of 'a'

printf("%p", ptr);  // Prints address (e.g., 0x7ffee...)
printf("%d", *ptr); // Prints value at that address (10)

2. Why Pointers? 🤔

1. Direct Memory Access: Hardware programming ke liye.
2. Call by Reference: Functions me original value change karne ke liye.
3. Dynamic Memory: malloc aur calloc use karne ke liye.

3. Pointer Arithmetic 🧮

Pointer + 1 ka matlab “Agla Address” (Bytes me jump). Agar int pointer hai (4 bytes), to ptr + 1 4 bytes aage jayega.

int arr[] = {10, 20, 30};
int *p = arr;

printf("%d", *p);       // 10
printf("%d", *(p + 1)); // 20 (Agla element)

4. Double Pointer (**) 🤯

Pointer ka bhi address ho sakta hai!

int a = 5;
int *p = &a;
int **q = &p; // Pointer to a Pointer w