使用java 使用定义和对象创建

Question

3个小问题 烦请解决一下一点不会
用定义等面对对象的基本知识解决这些问题！

Answer 1

// 第一个
public class FuelPrice {
    private String fuelType;
    private double fuelPrice;

    public FuelPrice(String fuelType, double fuelPrice) {
        this.fuelType = fuelType;
        this.fuelPrice = fuelPrice;
    }

    public void initFuelPrice(String fuelType, double fuelPrice) {
        this.fuelType = fuelType;
        this.fuelPrice = fuelPrice;
    }
}

第二个

public class FuelCard {
    private String cardID;
    private String cardNumber;
    private String cardPWD;
    private double chargeSum;
    private double cardBalance;

    public FuelCard(String cardID, String cardNumber, String cardPWD, double chargeSum, double cardBalance) {
        this.cardID = cardID;
        this.cardNumber = cardNumber;
        this.cardPWD = cardPWD;
        this.chargeSum = chargeSum;
        this.cardBalance = cardBalance;
    }

    public void initFuelCard(String cardID, String cardNumber, String cardPWD, double chargeSum, double cardBalance) {
        this.cardID = cardID;
        this.cardNumber = cardNumber;
        this.cardPWD = cardPWD;
        this.chargeSum = chargeSum;
        this.cardBalance = cardBalance;
    }

    public void displayInfo() {
        System.out.println("Card ID: " + cardID);
        System.out.println("Card Number: " + cardNumber);
        System.out.println("Card Password: " + cardPWD);
        System.out.println("Charge Sum: " + chargeSum);
        System.out.println("Card Balance: " + cardBalance);
    }

    // Getters and setters 方法就省略了，自己加上就好
   
}

第三个

public class FuelChargeDemo {
    public static void main(String[] args) {
        // 创建一张加油卡
        FuelCard fuelCard = new FuelCard("201512120001", "山IA66666", "123456", 1000.0, 800.0);

        // 输出加油卡信息
        fuelCard.displayInfo();
    }
}