Pointers in C language
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The document discusses pointers in C programming, explaining that a pointer is a variable that stores the address of another variable. It highlights the necessity of matching data types between a pointer and the variable it points to and introduces the concept of pointers to pointers. An example C program illustrates the usage of pointers and pointers to pointers in accessing variable values and addresses.
Pointers in C language
- 1. Pointers in C By: Prof. Ganesh Ingle
- 2. Course Main Topic/Chapters Introduction Declaration of pointers & pointer to pointer Concept of Pointer & Pointer to Pointer
- 3. Introduction 1. A pointer is a variable whose value is the address of another variable, i.e., direct address of the memory location. Like any variable or constant, you must declare a pointer before using it to store any variable address. 2. The actual data type of the value of all pointers, whether integer, float, character, or otherwise, is the same, a long hexadecimal number that represents a memory address. The only difference between pointers of different data types is the data type of the variable or constant that the pointer points to.
- 4. Declaration of a pointer
- 5. Concept of Pointer & Pointer to Pointer 1. If user want to store address of “a” which is of integer datatype to the pointer variable then the pointer should be of same data type, i.e. integer. 2. Pointer variable stores address of another variable of similar data type 3. Pointer to pointer variable stores address of another pointer of similar data type
- 6. Concept of Pointer & Pointer to Pointer 1. // C program to demonstrate pointer and pointer to pointer 2. #include <stdio.h> 3. #include <conio.h> 4. #include <math.h> 5. #include <string.h> 6. void main() 7. { 8. 9. int a = 145; 10. 11. // pointer for a 12. int *ptr2; 13. 14. // double pointer for ptr2 15. int **ptr1; 16. 17. // storing address of a in ptr2 18. ptr2 = &a; 19. 20. // Storing address of ptr2 in ptr1 21. ptr1 = &ptr2; 22. 23. // Displaying value of a using 24. // both single and double pointers 25. printf("Value of a = %dn", a ); 26. printf("Value of a using single pointer = %dn", *ptr2 ); 27. printf("Value of a using double pointer = %dn", **ptr1); 28. 29. printf("Address of a = %un", &a ); 30. printf("Address of a using single pointer = %un", ptr2 ); 31. printf("Address of a using single pointer = %un", *ptr1); 32. 33. printf("Address of ptr2 using ptr2 = %un", &ptr2 ); 34. printf("Address of ptr2 using ptr1 pointer to pointer = %un", ptr1 ); 35. 36. }