Why can’t static methods be abstract in Java?
In Java, a static method cannot be abstract. Doing so will cause compilation errors.
The above code is incorrect as static methods cannot be abstract. When run, the Compilation Error that occurs is:
prog.java:12: error: illegal combination of modifiers: abstract and static abstract static void func(); ^ 1 error
What will happen if a static method is made abstract?
Assuming we make a static method abstract. Then that method will be written as:
public abstract static void func();
- Scenario 1: When a method is described as abstract by using the abstract type modifier, it becomes responsibility of the subclass to implement it because they have no specified implementation in the super-class. Thus, a subclass must override them to provide method definition.
- Scenario 2: Now when a method is described as static, it makes it clear that this static method cannot be overridden by any subclass (It makes the static method hidden) as static members are compile-time elements and overriding them will make it runtime elements (Runtime Polymorphism).
Now considering Scenario 1, if the func method is described as abstract, it must have a definition in the subclass. But according to Scenario 2, the static func method cannot be overridden in any subclass and hence it cannot have a definition then. So the scenarios seem to contradict each other. Hence our assumption for static func method to be abstract fails. Therefore, a static method cannot be abstract.
Then that method will be coded as:
public static void func();
Static method implemented. Abstract method implemented.