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  1. #include <iostream>
  2.  
  3. using namespace std;
  4.  
  5. void swap1(int a, int b){	// passing by value
  6. 	int c = a;
  7. 	a = b;
  8. 	b = c;
  9. }
  10.  
  11. void swap2(int* a, int* b){	// pointer method (requires passing memory address (&var) instead of var)
  12. 	int c = *a;		// store value at a into c
  13. 	*a = *b;		// assign b's value to a's value
  14. 	*b = c;			// assign c to b's value
  15. }
  16.  
  17. void swap3(int& a, int& b){	// pass by reference
  18. 	int c = a;
  19. 	a = b;
  20. 	b = c;
  21. }
  22.  
  23. int main(){
  24. 	int a = 5;
  25. 	int b = 3;
  26. 	swap1(a, b);		// doesn't swap
  27. 	cout << "a=" << a << ", b=" << b << endl;
  28.  
  29. 	swap2(&a, &b);		// swaps with pointers
  30. 	cout << "a=" << a << ", b=" << b << endl;
  31.  
  32. 	swap3(a, b);		// swaps with references
  33. 	cout << "a=" << a << ", b=" << b << endl;
  34.  
  35. 	int* ra = &a;
  36. 	int* rb = &b;
  37. 	int y = *ra;
  38. 	(*ra)++;
  39. 	y = *ra;
  40.  
  41. 	return 0;
  42. }
Success #stdin #stdout 0.02s 2724KB
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Standard input is empty
stdout
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a=5, b=3
a=3, b=5
a=5, b=3
https://ideone.com/3c5mJ
language:
C++ (gcc 8.3)
created:
11 years ago
visibility:
public

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