Thir

src/main/java/mathlearning/service/MultipleChoiceGenerator/MultipleChoiceGenerator.java

@@ -9,10 +9,12 @@ public class MultipleChoiceGenerator {
     String[] QuestionList ;
     String[] AnswerList   ;
     String[] ChoiceList   ;
+    String[] CorrectAnswerNo;
 
-    MultipleChoiceGenerator(int count, User nowUser){// 如此声明MultipleChoiceGenerator实例,再调用下面三个接口
+    public MultipleChoiceGenerator(int count, User nowUser){// 如此声明MultipleChoiceGenerator实例,再调用下面三个接口
         this.QuestionList = new String[count];
         this.ChoiceList   = new String[count];
+        this.CorrectAnswerNo   = new String[count];
         this.QuestionList = SetQuestionList(count, nowUser);
         SetChoiceList();
     }
@@ -29,10 +31,14 @@ public class MultipleChoiceGenerator {
         return this.AnswerList;
     }
 
+    public String[] GetCorrectAnswerNo(){
+        return this.CorrectAnswerNo;
+    }
+
     private void SetChoiceList(){
         for(int i = 0 ; i < this.AnswerList.length ; i++){
             Random random = new Random();
-            String[] choiceNo = {"A.","B.","C.","D."};
+            String[] choiceNo = {"A","B","C","D"};
             String[] choices = new String[4];
             double correctChoice = Double.parseDouble(this.AnswerList[i]);
             int position = random.nextInt(4);
@@ -44,11 +50,14 @@ public class MultipleChoiceGenerator {
                     double choice = correctChoice;
                     double offset = random.nextInt(41) - 20;
                     choice += offset;
-                    choices[j] =choiceNo[j] + String.format("%.2f", choice);
+                    choices[j] =choiceNo[j] +"." + String.format("%.2f", choice);
+                }
+                else{
+                    CorrectAnswerNo[i] = choiceNo[j];
                 }
             }
 
-            this.ChoiceList[i] = String.join("\n", choices);
+            this.ChoiceList[i] = String.join("   ", choices);
         }
     }