Question

FOR C PROGRAMMING LANGUAGE

Draw the main memory diagram as captured at the end of the C program (i.e. return 0; statement). Your diagram must clearly shows where str, p1, p2, and p3 are pointing to, when the program terminates.

int main(void) {
char str[] = "cs111 NYU"; char* p1 = str;
p1 ++;
char** p2 = &p1;
char* p3 = &str[4];

printf("1. str = %s\n", p1); if(p3 - p1 == 4) {

printf("2. p1 == p3\n"); }

printf("3. char1 %c, char2 %c\n", *(*p2 + 2) + 1, *(*p2 + 2 + 1));

return 0; }

Answer 1

Here is the full memory diagram of above program --->

number written below any box tells address of that memory block in main memory and value in the box tells value stored at that memory address in main memory.

Char *p1 = str; // p1 = 2000

p1

2000

5000

p1++;

p1 *p1 = ‘s’

2001

5000

Char *p2 = &p1;

p2

5000

7000

p3 = &str[4];

p3 *p3 = ‘1’

2004

8000

clearly p3-p1 ===2004-2001 = 3

*p2 = 2000

*p2+2 = 2002

*(p2+2) +1= ‘1’+1 = ‘2’

*(*p2+2+1) = value at address 2003 which is 1

output of program

1. str = s111 NYU
3. char1 2, char2 1