從Java中的ArrayList打印元素

我有一個保存ArrayList的類。我想通過調用testClass中的getOrderItems方法來打印該數組中的所有項目。我遇到了麻煩，數組元素返回的方式。從Java中的ArrayList打印元素

這裏是類：

package shopping; 

import java.util.ArrayList; 

public class ShoppingCart { 
    private ArrayList<Item> list; 


    public ShoppingCart() { 
     this.list = new ArrayList<Item>(5); 
    } 

    public void addItem(Item item1) { 
     this.list.add(item1); 
    } 

    public int getTotal() { 
     int total = 0; 

     for(Item it : list) { 
      total = total + it.getCost(); 
     } 
     return total; 
    } 

    public void removeItem(Item item1) { 
     this.list.remove(item1); 
    } 

    public int finalizeOrder() { 
     int cartSize = this.list.size(); 
     return cartSize; 
    } 

    //print elements from ArrayList<Item> 
    public String getOrderItems() { 
     System.out.println(this.list); 
    return null; 
    } 

}

下面是從TestClass中塊：

//email possible & create 
     int emailPossible = card.verifyCard(); 
     if (emailPossible > 0) { 
      System.out.println("Email object has been added"); 
      System.out.println("Your orders was successful and has been placed.\nHere are the details of your order: \n"); 
      System.out.println("Items:\n------"); 
      System.out.println(cart.getOrderItems()); 
     }else{ 
      System.out.println("Email object has not been added"); 
     } 
     //end email possible & create

然而，我的輸出似乎是打印每個項目的地址，而不是項目本身：

Email object has been added 
Your orders was successful and has been placed. 
Here are the details of your order: 

Items: 
------ 
[[email protected], [email protected], [email protected]] 
null

來源

2016-09-28 Kuyashi

或者覆蓋[Object＃toString]（https://docs.oracle.com/javase/7/docs/api/java/lang/Object.html#toString（））或訪問您想要打印的字段一個方法。 – SomeJavaGuy

您應該覆蓋的toString()方法10班。它將允許您以自定義的方式打印其對象。

來源

2016-09-28 10:48:59

通過在類中重寫對象的超類方法來實現toString，您將能夠將列表打印爲字符串而不是引用。

來源

2016-09-28 10:49:18

從Java中的ArrayList打印元素

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