protecteddata.java

来自「java编程思想第四版习题答案」· Java 代码 · 共 24 行

// access/ProtectedData.java
// TIJ4 Chapter Access, Exercise 6, page 228
/* Create a class with protected data. Create a second class in the same file with
* a method that manipulates the protected data in the first class.
*/

class SomeData {
	protected int a = 13;
}

class DataChanger {
	static void change(SomeData sd, int i) { sd.a = i; }
}

public class ProtectedData {
	public static void main(String[] args) {
		SomeData x = new SomeData();
		System.out.println(x.a);
		DataChanger.change(x, 99);
		System.out.println(x.a);
	}
}