Java 中 Enum 数据类型的 equals 和 == 运算符
我们用四个常量定义了 Devices 枚举。
enum Devices {
LAPTOP, MOBILE, TABLET, DESKTOP;
}我们创建了几个对象并用常量为它们赋值。
让我们使用 equals() 和 == 来比较它们。首先,从 equals() 开始 −
if(d1.equals(d2))
System.out.println("Devices are the same.");
else
System.out.println("Devices are different.");现在,让我们继续操作并检查 ==
if(d1 == d3)
System.out.println("Devices are the same.");
else
System.out.println("Devices are different.");以下是同時說明 equals() 和 == 运算符的最終範例 −
範例
public class Demo {
enum Devices {
LAPTOP, MOBILE, TABLET, DESKTOP;
}
public static void main(String[] args) {
Devices d1, d2, d3, d4;
d1 = Devices.LAPTOP;
d2 = Devices.LAPTOP;
d3 = Devices.TABLET;
d4 = Devices.DESKTOP;
if(d1.equals(d2))
System.out.println("Devices are the same.");
else
System.out.println("Devices are different.");
if(d1 == d3)
System.out.println("Devices are the same.");
else
System.out.println("Devices are different.");
}
}輸出
Devices are the same. Devices are different.
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