1

所以这是我的代码中包含构造函数的部分。如您所见，目的是让构造函数接受更少的参数并调用最具体的构造函数。我以为我在第一个构造函数中启动了我的值。为什么找不到我的符号？

这是我的代码：

 public class Frog{

// instance variables 
 private String name;
 private int  age;
 private double tongueSpeed;
 private boolean isFrogLet;
 private  String species;

**// Third constructor** 
public Frog( String Name){
 this(Name, Age, TongueSpeed, IsFrogLet, Species);
 
 }


**//second constructor** 
 public Frog(String Name, int ageInYears, double TongueSpeed){
   this(Name, Age, TongueSpeed, IsFrogLet, Species);
   name= Name;
   age = ageInYears;
   tongueSpeed= TongueSpeed;
 }

**// most specific constructor**
 public Frog( String Name, int age, double TongueSpeed, boolean IsFrogLet, String Species){
   name = Name;
   this.age = Age;
   tongueSpeed = TongueSpeed;
   isFrogLet= IsFrogLet;
   species = Species;
 }

public void grow(int months){
 age = age + months;
 while ( age < 12){
  tongueSpeed++;
 }
 if (age>5 & age>30){
  double highRes= age-30;
  tongueSpeed= tongueSpeed-highRes;
 }
 if (age>1 & age <7){
  isFrogLet = true;
 }
}

}

- 这是我得到的错误：

Frog.java:12: error: cannot find symbol
 this(Name, Age, TongueSpeed, IsFrogLet, Species);
            ^
  symbol:   variable Age
  location: class Frog
Frog.java:12: error: cannot find symbol
 this(Name, Age, TongueSpeed, IsFrogLet, Species);
                 ^
  symbol:   variable TongueSpeed
  location: class Frog
Frog.java:12: error: cannot find symbol
 this(Name, Age, TongueSpeed, IsFrogLet, Species);
                              ^
  symbol:   variable IsFrogLet
  location: class Frog
Frog.java:12: error: cannot find symbol
 this(Name, Age, TongueSpeed, IsFrogLet, Species);
                                         ^
  symbol:   variable Species
  location: class Frog
Frog.java:19: error: cannot find symbol
   this(Name, Age, TongueSpeed, IsFrogLet, Species);
              ^
  symbol:   variable Age
  location: class Frog
Frog.java:19: error: cannot find symbol
   this(Name, Age, TongueSpeed, IsFrogLet, Species);
                                ^
  symbol:   variable IsFrogLet
  location: class Frog
Frog.java:19: error: cannot find symbol
   this(Name, Age, TongueSpeed, IsFrogLet, Species);
                                           ^
  symbol:   variable Species
  location: class Frog
Frog.java:28: error: cannot find symbol
   this.age = Age;
              ^
  symbol:   variable Age
  location: class Frog
4

3 回答 3

3

我认为您对构造函数重载的概念有所误解。**// Third constructor**仅输入名称，但您仍在尝试将其他内容传递给this. 如果东西不存在，你就不能传递它。因此，传递来自参数的内容并将其他内容设置为null：

public Frog( String Name){
   this(Name, 0, 0.0, false, null));
}

同样适用于其他构造函数。查看具体构造函数的参数是什么，并将其他内容设置为null.

于 2020-06-20T20:53:57.097 回答
1

该错误是不言自明的。在将它们传递给最具体的构造函数之前，您不会在第二个和第三个构造函数中创建具有特定名称的变量。
您应该将您在构造函数中收到的确切变量传递给底层构造函数，或者您应该将一些默认值传递给最具体的构造函数，而不是这些变量（又名符号）。
所以你应该通过以下方式调用你的第二个和第三个构造函数：

// Third constructor
public Frog(String Name) {
    this(Name, 0, 0.0, false, "");
}


//second constructor
public Frog(String Name, int ageInYears, double TongueSpeed) {
    this(Name, ageInYears, TongueSpeed, false, "");
}

希望这可以帮助

于 2020-06-20T20:56:25.037 回答
0

错误原因

您正在使用不存在的变量，因为您的实例级别在 camelCase 中没有在标题中除此之外的案例变量请查找重构代码并尝试使用 camelCase 作为变量

public class Frog {
    private String name;
    private int age;
    private double tongueSpeed;
    private boolean isFrogLet;
    private String species;

    public Frog(String name, int age, double tongueSpeed, boolean isFrogLet, String species) {
        this.name = name;
        this.age = age;
        this.tongueSpeed = tongueSpeed;
        this.isFrogLet = isFrogLet;
        this.species = species;
    }

    public Frog(String name) {
        this.name = name;
    }

    public Frog(String name, int ageInYears, double TongueSpeed) {
        this.name = name;
        this.age = ageInYears;
        this.tongueSpeed = TongueSpeed;
    }

    public void grow(int months) {
        age = age + months;
        while (age < 12) {
            tongueSpeed++;
        }
        if (age > 5 & age > 30) {
            double highRes = age - 30;
            tongueSpeed = tongueSpeed - highRes;
        }
        if (age > 1 & age < 7) {
            isFrogLet = true;
        }
    }

}
于 2020-06-20T21:02:35.990 回答