mylab1.java

经典java教材《java完美经典》一书中源码的完全收集

package j02080201.Pack1;
import java.lang.*;

public class myLab1
{  
  public void testfun()
	{      //测试直接存取 animal 类内定义的成员
	  /* 整段都会有错误  
		System.out.println("in myLab1 IQ = " + IQ);
		setIQ(60); //public
		System.out.println("in myLab1 LabArea = " + LabArea);		
		System.out.println("in myLab1 DNA = " + DNA);			
		System.out.println("in myLab1 height = " + height); //public
		System.out.println("in myLab1 weight = " + weight); //public
		*/
		System.out.println("myLab1 不是 animal 的子孙类，\n"
		                     + "不具有 animal 类的成员");
	}

	public static void main(String para[])
  {               //测试使用 animal 类对象的成员
		animal Obj3 = new animal();
		Obj3.height = 165;
		Obj3.weight = 50;
		
		//System.out.println("Obj3.IQ = " + Obj3.IQ);  //错误， private 成员只在 animal 内可见
		Obj3.setIQ(140); //改用 public 接口函数
		
		System.out.println("Obj3.LabArea = " + Obj3.LabArea);		
		
		System.out.println("Obj3.DNA = " + Obj3.DNA);  
		   //myLab1 和 animal 在同一个 package，可使用 protected 成员

		System.out.println("Obj3.height = " + Obj3.height);
		System.out.println("Obj3.weight = " + Obj3.weight);
  }	
}