DiscountStrategy.java
abstract public class DiscountStrategy {
private double price = 0;
private int copies = 0; public DiscountStrategy(double price, int copies) {
} public abstract double calculateDiscount();
}NoDiscountStrategy.java
public class NoDiscountStrategy
extends DiscountStrategy {
private double price = 0;
private int copies = 0; public NoDiscountStrategy(double price, int copies) {
this.price = price;
this.copies = copies;
} public double calculateDiscount() {
return price * copies;
}
}为什么要报错?
"NoDiscountStrategy.java": cannot resolve symbol: constructor DiscountStrategy ()in class test.strategy.DiscountStrategy at line 8, column 55
"NoDiscountStrategy.java": Object() in java.lang.Object is not defined in a public class or interface; cannot be accessed from outside package at line 8, column 55这个是为什么呀?
abstract public class DiscountStrategy {
private double price = 0;
private int copies = 0; public DiscountStrategy(double price, int copies) {
} public abstract double calculateDiscount();
}NoDiscountStrategy.java
public class NoDiscountStrategy
extends DiscountStrategy {
private double price = 0;
private int copies = 0; public NoDiscountStrategy(double price, int copies) {
this.price = price;
this.copies = copies;
} public double calculateDiscount() {
return price * copies;
}
}为什么要报错?
"NoDiscountStrategy.java": cannot resolve symbol: constructor DiscountStrategy ()in class test.strategy.DiscountStrategy at line 8, column 55
"NoDiscountStrategy.java": Object() in java.lang.Object is not defined in a public class or interface; cannot be accessed from outside package at line 8, column 55这个是为什么呀?
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}class B extends A {
public B() {
// 这里隐含调用super()
// 所以如果A类没有无参数构造函数就会报错
}
}楼主问题同此
super(price,copies);//显示调用
this.price = price;
this.copies = copies;
}
private int i = 0;
private double d = 0.0;
public A(int iVal,double dVal){
}
abstract public void discount(int iData,double dData);
}
public class ExClass extends A{
private int i = 0;
private double d =0.0;
public ExClass(int ii,double dd){
super(ii,dd);
i = ii;
d = dd;
}
public void discount(int iData,double dData){
i = iData;
d = dData;
}
public double getValue(){
return i*d;
}
}