this关键字：
1、总是指向当前对象
2、在一个构造方法中调用另一个构造方法，必须是构造函数的第一条语句
this 总是指向当前对象的引用
public class Product {
private String productName;
private int quantity;
private double price;
private double totalPrice;
public double computerTotalPrice() {
return price * quantity;}
public void show() {
System.out.println("\t" + "产品：" + productName);
System.out.println("\t" + "数量：" + quantity);
System.out.println("\t" + "价格：" + price);
System.out.println("\t" + "总价：" + this.computerTotalPrice());
System.out.println("**************************");}
public Product() {}
public Product(String productName, int quantity, double price) {
this.price = price;
this.productName = productName;
this.quantity = quantity;
}
//set get函数，用来调用私有化变量
public void setproductName(String productName) {
this.productName = productName;}
public String getproductName() {
return productName;}
public void setQuantity(int quantity) {
this.quantity = quantity;}
public int getQuantity() {
return quantity;}
public void setPrice(double price) {
this.price = price;}
public double getPrice() {
return price;}
public void setTotalPrice(double totalPrice) {
this.totalPrice = totalPrice;}
public double getTotalPrice() {
return totalPrice;}
}```
对象数组：
```javaStudent stud = new Student[ 3 ];``` //数组中只能存放Student对象或者子类对象
```java
public class Exend1 {
public static void main(String[] agrs) {
System.out.println("产品订单" + "-------------------");
Product[] pro = new Product[3];
pro[0] = new Product("蓝球", 5, 80.0);
pro[1] = new Product("VCD带", 6, 25.0);
pro[2] = new Product("钢笔", 3, 12.0);
for (int i = 0; i < pro.length; i++) {
pro[i].show();
}
// for( Product i : pro ) {
// i.show();
// }
System.out.println( "\n" );
}
}```
对象数组在内存中的存放：
