outer.java

来自「国外的数据结构与算法分析用书」· Java 代码 · 共 46 行

/**	The outer class. */
public class Outer
{
	/**	Instance variable known to Outer and Inner. */
	private int a;

	/**	A reference to an instance of Inner. */
	private Inner b;

	public Outer(int a)
	{
		this.a = a;
		b = new Inner(a * 2);
	}

	/**	Call a method on the inner class. */
	public int foo()
	{
		return b.foo2();
	}
	
	/**	The inner class. */
	public class Inner
	{
		/**	Instance variable only known to Inner. */
		private int b;

		public Inner(int b)
		{
			this.b = b;
		}

		/**	Method using instance variables from Outer and Inner. */
		public int foo2()
		{
			return a + b;
		}
	}

	/**	Starting point of the program. */
	public static void main(String[] args)
	{
		Outer test = new Outer(5);
		System.out.println(test.foo());
	}
}