发布时间 : 星期五 文章JAVA程序设计-答案更新完毕开始阅读d3c2a41d10a6f524ccbf852b
}
public int mileage;
private static final int TOP_SPEED = 50; abstract void alert();
public static int getTopSpeed() { return TOP_SPEED;
}
public void setCarName() { carName = \; }
public void setMileage() { mileage = 180; }
5.找出下面代码的错误部分,说明错误类型及原因,并更正之。 public class Car {
private String carName; public int mileage;
private static final int TOP_SPEED = 200; abstract void alert();
public static int getTopSpeed() { return TOP_SPEED; }
public static void setCarName() { carName = \奥迪\ }
public static void setMileage() { mileage = 180; } }
错误:因为含有抽象方法的类,必须是抽象类;静态方法只能访问静态成员。 更正:
public abstract class Car {
private String carName; public int mileage;
private static final int TOP_SPEED = 200; abstract void alert();
public static int getTopSpeed() { return TOP_SPEED; }
public void setCarName() { carName = \奥迪\;
}
public void setMileage() { mileage = 180; } }
6.下列代码不能编译的原因是:( )。 class A {
private int x;
public static void main(String args[]) { new B(); } class B { B() {System.out.println(x); } } }
因为在A类的main方法中,还没有A的实例就要试图生成内部类的实例。 更正如下: public class A { private int x;
public static void main(String args[]) { A a = new A(); a.new B(); }
class B { B() {
System.out.println(x);
} } }