定义多个构造方法完成对手机类属性的赋值。
时间: 2023-05-31 20:06:51 浏览: 73
假设我们的手机类有三个属性:品牌、型号、价格,那么可以定义如下的多个构造方法:
1. 不带参数的构造方法:
```java
public class Phone {
private String brand;
private String model;
private double price;
public Phone() {
this.brand = "unknown";
this.model = "unknown";
this.price = 0.0;
}
}
```
2. 带一个参数的构造方法,用于设置品牌:
```java
public class Phone {
private String brand;
private String model;
private double price;
public Phone() {
this.brand = "unknown";
this.model = "unknown";
this.price = 0.0;
}
public Phone(String brand) {
this.brand = brand;
this.model = "unknown";
this.price = 0.0;
}
}
```
3. 带两个参数的构造方法,用于设置品牌和型号:
```java
public class Phone {
private String brand;
private String model;
private double price;
public Phone() {
this.brand = "unknown";
this.model = "unknown";
this.price = 0.0;
}
public Phone(String brand) {
this.brand = brand;
this.model = "unknown";
this.price = 0.0;
}
public Phone(String brand, String model) {
this.brand = brand;
this.model = model;
this.price = 0.0;
}
}
```
4. 带三个参数的构造方法,用于设置品牌、型号和价格:
```java
public class Phone {
private String brand;
private String model;
private double price;
public Phone() {
this.brand = "unknown";
this.model = "unknown";
this.price = 0.0;
}
public Phone(String brand) {
this.brand = brand;
this.model = "unknown";
this.price = 0.0;
}
public Phone(String brand, String model) {
this.brand = brand;
this.model = model;
this.price = 0.0;
}
public Phone(String brand, String model, double price) {
this.brand = brand;
this.model = model;
this.price = price;
}
}
```
这样,我们就可以根据需要选择不同的构造方法来创建手机对象,例如:
```java
Phone phone1 = new Phone(); // 使用默认构造方法创建手机对象
Phone phone2 = new Phone("Apple"); // 使用带一个参数的构造方法创建手机对象
Phone phone3 = new Phone("Samsung", "Galaxy S21"); // 使用带两个参数的构造方法创建手机对象
Phone phone4 = new Phone("Xiaomi", "Mi 11", 3999.0); // 使用带三个参数的构造方法创建手机对象
```