java - 接口(interface)的所有方法都是抽象的吗？

Question

我看到它写在大多数地方-

"All of the methods in an interface are abstract."

但是接口(interface)也可能包含默认方法和静态方法，并且存在默认方法和静态方法的方法体。

那么接口(interface)的所有方法都是抽象的吗？

Answer 1

从 Java 8 开始，接口(interface)还可以包含默认方法和静态方法以及抽象方法。存在默认方法和静态方法的方法体。

One of the biggest design change in Java 8 is with the concept of interfaces. Prior to Java 7, we could have only method declarations in the interfaces. But from Java 8, we can have default methods and static methods in the interfaces.

Interface Default Method

For creating a default method in the interface, we need to use “default” keyword with the method signature.

Interface static methods

Static methods are similar to default methods except that we can’t override them in the implementation classes. This feature helps us in avoiding undesired results incase of poor implementation in child classes.

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