JAVA中equals()方法的重要性

對於對象比較使用equals()方法的重要性，這裡以String類為例進行了比較。

1. /**
2. * 對於對象比較使用equals()方法的重要性，這裡以String類為例進行了比較。
3. * @author HAN
4. *
5. */
6. public class TestEqual {
7. public TestEqual(){
8. testMethod();
9. }
10. void testMethod(){
11. String str=new String("Gaowen HAN");
12. String str2=new String("Gaowen HAN");
13. String str3="Gaowen HAN";
14. String str4="Gaowen HAN";
16. if(str.equals(str2)){
17. System.out.println("str is equal to str2");
18. }else{
19. System.out.println("str is not equal to str2");
20. }
22. if(str3==str4){
23. System.out.println("str is equal to str2");
24. }else{
25. System.out.println("str is not equal to str2");
26. }
28. if(str==str2){
29. System.out.println("str is equal to str2");
30. }else{
31. System.out.println("str is not equal to str2");
32. }
34. if(str.equals(str3)){
35. System.out.println("str is equal to str2");
36. }else{
37. System.out.println("str is not equal to str2");
38. }
40. if(str==str3){
41. System.out.println("str is equal to str2");
42. }else{
43. System.out.println("str is not equal to str2");
44. }
46. }
47. public static void main(String[] args) {
48. new TestEqual();
49. }
50. }