java测试

Java Program Design Examination
Name:
一、1. Which statement will compile wrong: ( B )
A if(3>5)System.out.println("hello");
B if (3)System.out.println("hello");
C if(true)System.out.println("hello");
D if(false)System.out.println("hello");
2. in java which one is not a Layout Management class: ( D )
A. BorderLayout
B. FlowLayout
C. CardLayout
D. LayoutManage
3. What happens when you try to compile and run the following program? ( B )
class Mystery{
public static void main(String[] args){ Mystery m=new Mystery(); }
void Mystery(){ System.out.println(”constructor”); }
}
A. this code will not compile
B. output ”null”
C. output nothing
D. output “constructor”
4. Given:
class A { A() { } }
class B extends A {} Which statement is true? ( d g )
A. Class B's constructor is public.
B. Class B's constructor has arguments.
C. Class B's constructor includes a call to this().
D. Class B's constructor includes a call to super().
5. 在下列程序中
1 class Bird{
2 int num;
3 void feather(int num) {
4 this.num = num;}}第4行中的程序this.num是指在程序中的哪一个num变量( A )
A. 第二行中的int num
B. 第三行中的int num
C. a、b选项都正确
D. a、b选项都不对
二 1. Inside a Java method definition, you can use the keyword this as a name for the calling object. (F)
2. Method overloading is when two or more methods of the same class have the same name but differ in number or types of parameters. ( T)
3. In a static method, you may use the this parameter either explicitly or implicitly. ( T )
4.Each …try‟ statement has only one corresponding …catch‟ statement.. ( F)
5. The compiler creates a default constructor only when there are no other constructors for the class. ( T )
三
四1、构造一个类来描述一个点，该类的构成包括点的x和y两个坐标，以及一些对点进行的操作，包括：取得点的坐标，对点的坐标进行赋值，编写程序生成该类的对象并对其进行操作。

2、定义接口Shape，抽象方法为showArea()，求出面积并显示，定义矩形类Rectangle,正方形类Square,圆类Circle，根据各自的属性，用showArea方法求出各自的面积，在main方法中构造3个对象，调用showArea方法。