先翻译:
实现一个java类名字叫做textBook,有两个属性 pages(int类型),和title(String).再写一个类叫做mathbook继承textbook同时又有可textBook的属性,同时有拥有两个自己的属性definitions,average.definitions类型是integer类型,average是double类型。mathbook有个一方法叫做getAverage(),打印和返回average
public class TextBook {
protected int pages;
protected String title;
}
class MathBook extends TextBook {
private Integer definitions;
private Double average;
public double getAverage() {
average = definitions / pages;
System.out.println(average);
return average ;
}
}
追问
追答没有main方法
public class TextBook {
protected int pages;
protected String title;
}
class MathBook extends TextBook {
private Integer definitions;
private double average;
public double getAverage() {
average = definitions / pages;
System.out.println(average);
return average;
}
public static void main(String[] args) {
new MathBook().getAverage();
}
}
追问
new mathBook().getAverage();是否缺引用语句
追答new mathBook().没传递参数进去改成这样就行了
new MathBook(111,2132).getAverage();
追问还是显示错误,The constructor mathBook(int,int) is unfinded
追答 // 忘记写构造了
private Integer definitions;
private double average;
public MathBook(Integer definitions,double average){
this.definitions = definitions;
this.average = average;
}
public double getAverage() {
average = definitions / pages;
System.out.println(average);
return average;
}
public static void main(String[] args) {
new MathBook(11,23.01).getAverage();
}
追问
求大神进一步解答
求大神进一步解答
追答// 没有初始化pages.所以是0,0不能为被除数
public class TextBook {
protected int pages;
protected String title;
}
class MathBook extends TextBook {
private Integer definitions;
private double average;
public double getAverage() {
average = (double)definitions / (double)pages;
System.out.println(average);
return average;
}
public static void main(String[] args) {
TextBook textBook = new TextBook();
textBook.pages = 10;
MathBook book = new MathBook();
book.definitions = 12;
book.getAverage();
}
}