Incrementing Pointer :
- Incrementing Pointer is generally used in array because we have contiguous memory in array and we know the contents of next memory location.
- Incrementing Pointer Variable Depends Upon data type of the Pointer variable
Formula : ( After incrementing )
new value = current address + i * size_of(data type)
Three Rules should be used to increment pointer -
Address + 1 = Address Address++ = Address ++Address = Address
Pictorial Representation :
| Data Type | Older Address stored in pointer | Next Address stored in pointer after incrementing (ptr++) |
|---|---|---|
| int | 1000 | 1002 |
| float | 1000 | 1004 |
| char | 1000 | 1001 |
Explanation : Incremeting Pointer
- Incrementing a pointer to an integer data will cause its value to be incremented by 2 .
- This differs from compiler to compiler as memory required to store integervary compiler to compiler
Note to Remember : Increment and Decrement Operations on pointer should be used when we have Continues memory (in Array).
Live Example 1 : Increment Integer Pointer
#include<stdio.h> int main(){ int *ptr=(int *)1000; ptr=ptr+1; printf("New Value of ptr : %u",ptr); return 0; }
Output :
New Value of ptr : 1002
Live Example 2 : Increment Double Pointer
#include<stdio.h> int main(){ double *ptr=(double *)1000; ptr=ptr+1; printf("New Value of ptr : %u",ptr); return 0; }
Output :
New Value of ptr : 1004
Live Example 3 : Array of Pointer
#include<stdio.h> int main(){ float var[5]={1.1f,2.2f,3.3f}; float(*ptr)[5]; ptr=&var; printf("Value inside ptr : %u",ptr); ptr=ptr+1; printf("Value inside ptr : %u",ptr); return 0; }
Output :
Value inside ptr : 1000 Value inside ptr : 1020
Explanation :
Address of ptr[0] = 1000
We are storing Address of float array to ptr[0]. -
Address of ptr[1] = Address of ptr[0] + (Size of Data Type)*(Size of Array) = 1000 + (4 bytes) * (5) = 1020
Address of Var[0]…Var[4] :
Address of var[0] = 1000 Address of var[1] = 1004 Address of var[2] = 1008 Address of var[3] = 1012 Address of var[4] = 1016