Question

I have some questions about pointers/pointer arithmetic in C++

1) Pointers and Pointer Arithmetic

a.)       What is the difference between statically allocated arrays and dynamically allocated arrays (be brief)

b.)      Which of the following pointers can be used for a dynamically allocated array? (Circle) char ptr; char * ptr; char ptr *; char ptr[]; char [] ptr;

c.)       Show now, using that pointer, how to dynamically allocate array of characters of size 10: (don't use malloc)

d.)      Which of the following will store an ‘a’ in the first element of the array: (Circle) ptr[1] = ‘a’; ptr[] = ‘a’; ptr = ‘a’; *ptr= ‘a’; *ptr[0] = ‘a’;

e.)      Show how to store the word “Highlander” into this array that has already been created:

f.)       How could you display just the last character of the word – if you didn’t know what element it was at?

 Using the subscript operator:  Using pointer arithmetic:

e.)   Release the dynamic memory used on this page:

Answer 1

a.)       What is the difference between statically allocated arrays and dynamically allocated arrays

Answer:

statically allocated arrays are stored on stack and dynamically allocated arrays are stored in heap.

b.)      Which of the following pointers can be used for a dynamically allocated array?

Answer:

char*ptr

c.)       Show now, using that pointer, how to dynamically allocate array of characters of size 10: (don't use malloc)

Answer:

ptr=new char[10];

d.)      Which of the following will store an ‘a’ in the first element of the array:

Answer:

*ptr= ‘a’;

e.)      Show how to store the word “Highlander” into this array that has already been created:

Answer:

Using strcpy function:

strcpy(ptr,Highlander);

f.)       How could you display just the last character of the word – if you didn’t know what element it was at?

 Using the subscript operator:

Answer:

cout<<ptr[strlen(ptr)-1];

Using pointer arithmetic:

Answer:

cout<<*(ptr+strlen(ptr)-1);

e.)   Release the dynamic memory used on this page:

Answer:

delete[] ptr