java 代码 1.package test; 2. 3.public class Test { 1. public static void main(String args[]) { 2. Integer interger1, interger2; 3. int i, j; 4. interger1 = new Integer(10); 5. interger2 = new Integer(50); 6. i = 5; 7. j = 9; 8. System.out.println("Before Swap, Interger1 is " + interger1); 9. System.out.println("Before Swap, Interger2 is " + interger2); 10. swap(interger1, interger2); 11. System.out.println("After Swap Interger1 is " + interger1); 12. System.out.println("After Swap Interger2 is " + interger2); 13. System.out.println("Before Swap i is " + i); 14. System.out.println("Before Swap j is " + j); 15. swap(i, j); 16. System.out.println("After Swap i is " + i); 17. System.out.println("After Swap j is " + j); 18. 19. StringBuffer sb = new StringBuffer("I am StringBuffer"); 20. System.out.println("Before change, sb is <" + sb + ">"); 21. change(sb); 22. System.out.println("After change sb is <" + sb + ">"); 23. } 24. 25. public static void swap(Integer ia, Integer ib) { 26. Integer temp = ia; 27. ia = ib; 28. ib = temp; 29. } 30. 31. public static void swap(int li, int lj) { 32. int temp = li; 33. li = lj; 34. lj = temp; 35. } 36. 37. public static void change(StringBuffer ia) { 38. ia.append(", but my content can be changed"); 39. //ia = new StringBuffer(",but my content can be changed"); 40. } 41.} 42. 输出:
Before Swap, Interger1 is 10 Before Swap, Interger2 is 50 After Swap Interger1 is 10 After Swap Interger2 is 50 Before Swap i is 5 Before Swap j is 9 After Swap i is 5 After Swap j is 9 Before change, sb is <I am StringBuffer> After change sb is <I am StringBuffer, but my content can be changed>