构造函数错误：如何通过参数化构造函数设置这些属性？

Question

1.如何通过参数化构造函数设置这些属性？？

类文件

public class Product{
    private String Name;
    private String Color;
    private int Price;
    private int Stock;
    private int SKU;
    

>

我想通过传递参数构造函数的setter设置这些属性，但它没有设置这些属性

public void setName(String Name){
    this.Name=Name;
}
public void setColor(String Color){
    this.Color=Color;
}
public void setPrice(int Price){
    if (Price <= 0){
        System.out.println("Price can't be 0 or negative");
    }
    else{this.Price=Price;
    }

}
public void setStock(int Stock){
    if(Stock == 0){
        System.out.println("Stock not avaible");
    }
    else{
        this.Stock=Stock;
    }

}
public void setSKU(int SKU){
    if(SKU<6){
        System.out.println("Manimum allow quntity is 6");
    }
    else{
        this.SKU=SKU;
    }
}

在这里，我想通过toString方法显示属性

public String toString(){
    return "\nProduct name: " + this.Name + "\nProduct color: " + this.Color + "\nProduct price: " + this.Price + "\nProduct stock: " + this.Stock + "\nProduct SKU: " + this.SKU;
}

Product(){}

//parametriaz constractor
Product(String Name,String Color,int Price,int Stock,int SKU){
    System.out.println("Run");
    setName(Name);
    setColor(Color);
    setPrice(Price);
    setStock(Stock);
    setSKU(SKU);
    toString();
}

}对象文件

为什么我无法通过构造函数设置这些属性？？

public class Runnable{public static void main（String[]args）{Product p1=新产品（“pc”，“Grey”，5000,10,2）；

        //This line also give error why??
        //p1.Product("pc","Grey",5000,10,2);
    }
}

Answer 1

按照惯例，字段名以大小写形式出现。

public class Product {
    private String name;
    private String color;
    private int price;
    private int stock;
    private int sku;

    Product() {
    }

    //Parameterized constructor
    Product(String name, String color, int price, int stock, int sku) {
        System.out.println("Run");
        this.setName(name);
        this.setColor(color);
        this.setPrice(price);
        this.setStock(stock);
        this.setSku(sku);
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getColor() {
        return color;
    }

    public void setColor(String color) {
        this.color = color;
    }

    public int getPrice() {
        return price;
    }

    public void setPrice(int price) {
        if (price <= 0) {
            System.out.println("Price can't be 0 or negative");
        } else {
            this.price = price;
        }

    }

    public int getStock() {
        return stock;
    }

    public void setStock(int stock) {
        if(stock == 0){
            System.out.println("Stock not avaible");
        }
        else{
            this.stock=stock;
        }
    
    }

    public int getSku() {
        return sku;
    }

    public void setSku(int sku){
        if(sku<6){
            System.out.println("Manimum allow quntity is 6");
        }
        else{
            this.sku=sku;
        }
    }

    @Override
    public String toString() {
        return "Product [color=" + color + ", name=" + name + ", price=" + price + ", sku=" + sku + ", stock=" + stock
                + "]";
    }



    //Consume
    public static void main(String[] args) {

        System.out.println("using Constructor only");
        Product p = new Product("pc","Grey",5000,10,2);   // Right way to call contructor
        System.out.println(p); // Prints the object using toString()
        
        //OR
        System.out.println(new Product("pc","Grey",5000,10,2));

        //OR
        System.out.println("using Setters and getters only");
        Product p1 = new Product();
        p1.setName("pc");
        p1.setColor("Grey");
        p1.setPrice(5000);
        p1.setStock(10);
        p1.setSku(2);

        System.out.println(p1);
    }

}

❯ java Product.java
using Constructor only
Run
Manimum allow quntity is 6
Product [color=Grey, name=pc, price=5000, sku=0, stock=10]
Run
Manimum allow quntity is 6
Product [color=Grey, name=pc, price=5000, sku=0, stock=10]
using Setters and getters only
Manimum allow quntity is 6
Product [color=Grey, name=pc, price=5000, sku=0, stock=10]