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Java 如何在类数组中分配元素_Java_Arrays - Fatal编程技术网

Java 如何在类数组中分配元素

Java 如何在类数组中分配元素,java,arrays,Java,Arrays,我有一个名为Tire的类,它有一个函数。我把它叫做Carclass。一辆汽车有4个轮胎,因此我需要在car类中将轮胎声明为一个数组,以便调用Tire类中实现的函数。我该怎么做呢 class Tire { public void pumpAir(int psi) {} } public class Car { private Tire[] tires = new Tire[4]; } public static void main(String[] args) { C

我有一个名为
Tire
的类,它有一个函数。我把它叫做
Car
class。一辆汽车有4个轮胎,因此我需要在
car
类中将轮胎声明为一个数组,以便调用
Tire
类中实现的函数。我该怎么做呢

class Tire {
    public void pumpAir(int psi) {}
}

public class Car {
    private Tire[] tires = new Tire[4];
}

public static void main(String[] args) {

    Car car = new Car();

    car.tires ... // how to call 3rd tire and pump it?
}

最好的选择是在汽车类中创建一个getter

public class Car 
{
    private Tire[] tires = new Tire[4];

    public Tire[] getTires() 
    {
        return tires;
    }
}
然后在main中,您可以通过

car.getTires()[2].pumpAir(someInt);

一个选项是为它创建一个getter:

public class Car {
    private Tire[] tires = new Tire[4];

    public Tire getTire(int i) {
        if (i >= 0 && i < tires.length) {
           return tires[i];
        }
        return null;
    }
}

为轮胎创建一个getter,并使用下标作为其private访问它
或者将访问说明符更改为public,并使用下标运算符访问它

public class Car {
    private Tire[] tires = new Tire[4];

    public Tire getTire(int number) {
         if(number >= 0 && number < tires.length) {
              return tires[number];
         } else {
              return null;
         }
    }

}

public static void main(String[] args) {

    Car car = new Car();

    car.getTire(2) ... // how to call 3rd tire and pump it?
}
公车{
私人轮胎[]轮胎=新轮胎[4];
公共轮胎(国际编号){
如果(编号>=0&&number<轮胎长度){
返回轮胎[数量];
}否则{
返回null;
}
}
}
公共静态void main(字符串[]args){
汽车=新车();
car.getTire(2)…//如何调用第三个轮胎并为其加油?
}
公共级轮胎
{
公共真空泵对(int psi){
系统输出打印项次(“轮胎编号”+psi+“泵送”);
}
}
公车{
私人轮胎[]轮胎=新轮胎[4];
公共汽车
{

对于(int i=0;i
汽车。轮胎[0]
将访问汽车中的第一个轮胎。@Eniss这是一项任务吗?你读过关于数组主题的课程材料吗?你尝试过什么?
public class Car {
    private Tire[] tires = new Tire[4];

    public Tire getTire(int number) {
         if(number >= 0 && number < tires.length) {
              return tires[number];
         } else {
              return null;
         }
    }

}

public static void main(String[] args) {

    Car car = new Car();

    car.getTire(2) ... // how to call 3rd tire and pump it?
}
 public class Tire 
    {
        public void pumpAir(int psi) {
                 System.out.println("Tire number " + psi + " pumped.");
         }
    }



 public class Car {
        private Tire[] tires = new Tire[4];



 public Car()
    {
     for(int i=0;i<4;i++)
         this.tires[i]=new Tire(); 
    }

public Tire[] getTiers()

   {
     return tires;
   }
}

public static void main(String[] args) {



 Car car = new Car();

// how to call 3rd tire and pump it?
car.getTiers()[2].pumpAir(2 + 1);

}