1. Pointers & Functions

2. Pointers and Functions
Functions can take pointers:
C equivalent to pass by ref
#include <iostream> using namespace std; //C++ style void doubleVariable(int& x) { x = x * 2; } //C style void doubleVariableCStyle(int* x) { *x = (*x) * 2; } int main() { int num = 10; cout << num << endl; doubleVariable(num); cout << num << endl; doubleVariableCStyle(&num); cout << num <<#include <iostream>
using namespace std;
//C++ style
void doubleVariable(int& x) {
x = x * 2; }
//C style
void doubleVariableCStyle(int* x) {
*x = (*x) * 2;
int main() {
int num = 10;
cout << num << endl;
doubleVariable(num);
doubleVariableCStyle(&num);
return 0;
endl; return 0; }

3. Passing Pointers
Pointers used like reference params: p1 p2 x 5 y 4

4. Passing Pointers Pointers used like reference params: temp p1 p2 x 5 y4

5. Passing Pointers Pointers used like reference params: temp 5 p1 p2 x 5y 4

6. Passing Pointers Pointers used like reference params: temp 5 p1 p2 x 4y 4

7. Passing Pointers Pointers used like reference params: temp 5 p1 p2 x 4y 5

8. Passing Pointers
Pointers used like reference params: p1 p2 x 4 y 5

9. Passing Pointers Directly passing pointers p1 p2 x 5 pt1 0x004 pt2

10. Passing Pointers Directly passing pointers – addresses copied
Can change x/y or p1/p2
Can't change pt1 / pt2 p1
0x004 p2
0x008 x 5
pt1
0x004
pt2
0x008 y 4

11. Passing Pointers Passing references to pointers p1 p2 x 5 pt1 0x004y 4

12. Passing Pointers References to pointers
temp
References to pointers
Can change the pointers themselves p1 p2 x 5
pt1
0x004
pt2
0x008 y 4

13. Passing Pointers References to pointers
temp
0x004
References to pointers
Can change the pointers themselves p1 p2 x 5
pt1
0x004
pt2
0x008 y 4

14. Passing Pointers References to pointers
temp
0x004
References to pointers
Can change the pointers themselves p1 p2 x 5
pt1
0x008
pt2
0x008 y 4

15. Passing Pointers References to pointers
temp
0x004
References to pointers
Can change the pointers themselves p1 p2 x 5
pt1
0x008
pt2
0x004 y 4

16. Passing Pointers References to pointers
Can change the pointers themselves p1 p2 x 5
pt1
0x008
pt2
0x004 y 4

17. Return Pointers
Can return a pointer from a function:

18. Returning Pointers
Can return pointer – better not be to local variable

19. Returning Pointers
Can return pointer – better not be to local variable x 10 pt

20. Returning Pointers
Can return pointer – better not be to local variable x 10 pt
0x110 p
0x110

21. Returning Pointers
Can return pointer – better not be to local variable p
0x110