Downloaded 22 times
![mohammed.sikander@cranessoftware.com 2
char *ptr_name = “SIKANDER”;
char str_name[ ] = “SIKANDER”;
• Can we make a pointer point to string literal?](https://image.slidesharecdn.com/pointer-level2-160802134210/85/Pointer-level-2-2-320.jpg)
![mohammed.sikander@cranessoftware.com 3
char *ptr_name = “SIKANDER”;
char str_name[ ] = “SIKANDER”;
printf(“ %s n“ , ptr_name);
printf(“ %s n“ , str_name);
• Can we print the string through pointer.](https://image.slidesharecdn.com/pointer-level2-160802134210/85/Pointer-level-2-3-320.jpg)
![mohammed.sikander@cranessoftware.com 4
char *ptr_name = “SIKANDER”;
char str_name[ ] = “SIKANDER”;
printf(“Length of %s = %dn“ , ptr_name , strlen(ptr_name));
printf(“Length of %s = %dn“ , str_name , strlen(str_name));](https://image.slidesharecdn.com/pointer-level2-160802134210/85/Pointer-level-2-4-320.jpg)
![mohammed.sikander@cranessoftware.com 5
char *ptr_name = “SIKANDER”;
char str_name[ ] = “MUQADDAR”;
printf(“Size of ptr_name = %dn“ , sizeof(ptr_name));
printf(“Size of str_name = %dn“ , sizeof(str_name));](https://image.slidesharecdn.com/pointer-level2-160802134210/85/Pointer-level-2-5-320.jpg)
![We can have arrays where each element
can be a pointer
int *
char **
int *
int *
int *
int *
int *arr_ptr[5];
int
int
int
int
int
int arr[5];
What is size of arr?
What is size of arr_ptr?](https://image.slidesharecdn.com/pointer-level2-160802134210/85/Pointer-level-2-9-320.jpg)
![char **
Char *arr_ptr[5];
char
*
char *
char *
char *
char *
char
char
char
char
char
Char arr[5];
What is size of arr?
What is size of arr_ptr?](https://image.slidesharecdn.com/pointer-level2-160802134210/85/Pointer-level-2-10-320.jpg)
![int x = 10;
int *ptr = &x;
int arr[5]
int *ptr = arr;
int a = 10;
int b = 23;
int arr[ ] = {12,34,54};
int *ptr[ ] = {&a , &b , arr};](https://image.slidesharecdn.com/pointer-level2-160802134210/85/Pointer-level-2-11-320.jpg)
![char *capitalCities[] = { “Bangalore”, “Chennai”,
“Guwahati”, “Amravathi”};
Bangalore
Chennai
Guwahati
Amravathi
*
*
*
*
char *
char *
char *
char *
char *str = “VxWorks”;](https://image.slidesharecdn.com/pointer-level2-160802134210/85/Pointer-level-2-12-320.jpg)
More Related Content
Pointer level 2
- 1. Prepared by Mohammed Sikander TechnicalLead Cranes Software International Limited
- 2. mohammed.sikander@cranessoftware.com 2 char *ptr_name= “SIKANDER”; char str_name[ ] = “SIKANDER”; • Can we make a pointer point to string literal?
- 3. mohammed.sikander@cranessoftware.com 3 char *ptr_name= “SIKANDER”; char str_name[ ] = “SIKANDER”; printf(“ %s n“ , ptr_name); printf(“ %s n“ , str_name); • Can we print the string through pointer.
- 4. mohammed.sikander@cranessoftware.com 4 char *ptr_name= “SIKANDER”; char str_name[ ] = “SIKANDER”; printf(“Length of %s = %dn“ , ptr_name , strlen(ptr_name)); printf(“Length of %s = %dn“ , str_name , strlen(str_name));
- 5. mohammed.sikander@cranessoftware.com 5 char *ptr_name= “SIKANDER”; char str_name[ ] = “MUQADDAR”; printf(“Size of ptr_name = %dn“ , sizeof(ptr_name)); printf(“Size of str_name = %dn“ , sizeof(str_name));
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- 9. We can havearrays where each element can be a pointer int * char ** int * int * int * int * int *arr_ptr[5]; int int int int int int arr[5]; What is size of arr? What is size of arr_ptr?
- 10. char ** Char *arr_ptr[5]; char * char* char * char * char * char char char char char Char arr[5]; What is size of arr? What is size of arr_ptr?
- 11. int x =10; int *ptr = &x; int arr[5] int *ptr = arr; int a = 10; int b = 23; int arr[ ] = {12,34,54}; int *ptr[ ] = {&a , &b , arr};
- 12. char *capitalCities[] ={ “Bangalore”, “Chennai”, “Guwahati”, “Amravathi”}; Bangalore Chennai Guwahati Amravathi * * * * char * char * char * char * char *str = “VxWorks”;
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- 14. names++ triesto change the base address of array. We cannot change the base address of array. Str was a pointer, names is an array. mohammed.sikander@cranessoftware.com 14
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- 18. Void pointerscan hold the address of any type of object. Dereferencing on void pointers are not allowed. Incrementing void pointers are not allowed.
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- 25. How manybytes of memory is leaked mohammed.sikander@cranessoftware.com 25
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Editor's Notes
- #21 #include <stdio.h> #include <stdlib.h> int main( ) { int *ptr = malloc(20); if(ptr == NULL) { printf("Unable to Allocate Memory..."); return 1; } //Assume allocation is successful printf("Allocation is successful... ptr = %p\n" , ptr); free(ptr); printf("After free... ptr = %p\n" , ptr); free(ptr); printf("After Second free... ptr = %p\n" , ptr); return 0; }
- #22 #include <stdio.h> #include <stdlib.h> int main( ) { int *ptr = malloc(20); if(ptr == NULL) { printf("Unable to Allocate Memory..."); return 1; } //Assume allocation is successful printf("Allocation is successful... ptr = %p\n" , ptr); free(ptr); printf("After free... ptr = %p\n" , ptr); free(ptr); printf("After Second free... ptr = %p\n" , ptr); return 0; }
- #25 #include <stdio.h> #include <stdlib.h> int main( ) { int *ptr1 = (int *)malloc(5 * 4); int *ptr2 = (int *)calloc(5 , 4); printf("Contents in memory allocated using malloc\n"); for(int i = 0 ; i < 5 ; i++) printf(" %d" , ptr1[i]); printf("\n"); printf("Contents in memory allocated using calloc\n"); for(int i = 0 ; i < 5 ; i++) printf(" %d" , ptr2[i]); printf("\n"); return 0; }
- #31 #include <stdio.h> #include <stdlib.h> void readArray( int arr[],int n ) { for(int i = 0 ; i < n ; i++) scanf(" %d" , &arr[i]); } void printArray( int arr[] , int n){ for(int i = 0 ; i < n ; i++) printf(" %d" , arr[i]); } int main() { int *ptr1 = malloc(20); printf("\n ptr1 = %p ",ptr1); printf("Enter elements in first block \n"); readArray(ptr1 , 5);//Assume 1,2,3,4,5 is entered free(ptr1); int *ptr2 = malloc(20); printf("\n ptr2 = %p ",ptr2); printf("Enter elements in second block \n"); readArray(ptr2 , 5); //Assume 6,7,8,9,10 is entered if(ptr1 != NULL){ printf("Elements of first block are \n"); printArray(ptr1 , 5); } if(ptr2 != NULL){ printf("Elements of second block are \n"); printArray(ptr2 , 5); } }