Java对象相等比较(Equals)
Posted SXT
tags:
篇首语：本文由小常识网(cha138.com)小编为大家整理，主要介绍了Java对象相等比较(Equals)相关的知识，希望对你有一定的参考价值。
以下代码显示如何实现equals()和hashCode()方法
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
|
class Point { private int x; private int y; public Point(int x, int y) { this.x = x; this.y = y; } /* implement the equals() method */ public boolean equals(Object otherObject) { // Are the same? if (this == otherObject) { return true; } // Is otherObject a null reference? if (otherObject == null) { return false; } // Do they belong to the same class? if (this.getClass() != otherObject.getClass()) { return false; } // Get the reference of otherObject in a SmartPoint variable Point otherPoint = (Point) otherObject; // Do they have the same x and y co-ordinates boolean isSamePoint = (this.x == otherPoint.x && this.y == otherPoint.y); return isSamePoint; } /* * implement hashCode() method of the Object class, which is a requirement * when you implement equals() method */ public int hashCode() { return (this.x + this.y); }}public class Main { public static void main(String[] args) { Point pt1 = new Point(10, 10); Point pt2 = new Point(10, 10); Point pt3 = new Point(12, 19); Point pt4 = pt1; System.out.println("pt1 == pt1: " + (pt1 == pt1)); System.out.println("pt1.equals(pt1): " + pt1.equals(pt1)); System.out.println("pt1 == pt2: " + (pt1 == pt2)); System.out.println("pt1.equals(pt2): " + pt1.equals(pt2)); System.out.println("pt1 == pt3: " + (pt1 == pt3)); System.out.println("pt1.equals(pt3): " + pt1.equals(pt3)); System.out.println("pt1 == pt4: " + (pt1 == pt4)); System.out.println("pt1.equals(pt4): " + pt1.equals(pt4)); }} |
上面的代码生成以下结果。
以上是关于Java对象相等比较(Equals)的主要内容，如果未能解决你的问题，请参考以下文章