使用循环的众多字符串值的总和

Question

在此处输入图像描述我有一个名为价格的字符串。我从 firebase 数据库中获取 Price 的值。我想将这些字符串值相加并得出总价。价格值根据数据库中的子项自动增加。例如，值为 100、70、50、20、40 等。它会相应地增加。

我认为应该有一个循环来使所有这些值的总和成为总价。

这就是我到目前为止所做的。

 int pos = 0;                                     

 JSONObject jsonObject = new JSONObject();

 if (jsonObject.has(Integer.toString(pos))) {

 } else {                                       

     try {                                               

         jsonObject.put(Integer.toString(pos),Price);                                         

     } catch (JSONException e) {                                           

         e.printStackTrace();                                         

     }                                    

 }

 for (int i = 0; i < jsonObj.length(); i++) {

     try {                                  

         String itemInArray = jsonObj.getString(String.valueOf(i));

         int Sum =  0;

         int totalPrice = sum + itemInArray;

  } catch (JSONException e) {

                                    e.printStackTrace();

                                }

                            }

但是代码不起作用。请提供任何帮助，我们将不胜感激。

Answer 1

&nbsp;int pos = 0;&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp;JSONObject jsonObject = new JSONObject();&nbsp;if (jsonObject.has(Integer.toString(pos))) {&nbsp;} else {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp; &nbsp; &nbsp;try {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;jsonObject.put(Integer.toString(pos),Price);&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp; &nbsp; &nbsp;} catch (JSONException e) {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;e.printStackTrace();&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp; &nbsp; &nbsp;}&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp;&nbsp;}&nbsp;for (int i = 0; i < jsonObj.length(); i++) {&nbsp; &nbsp; &nbsp;try {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp;&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;String itemInArray = jsonObj.getString(String.valueOf(i));&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;int Sum =&nbsp; 0;&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;int totalPrice = sum + itemInArray;&nbsp; } catch (JSONException e) {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; e.printStackTrace();&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; }&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; }但是代码不起作用。请提供任何帮助，我们将不胜感激。