在For循環中使用計數器？

Question

我該如何在這個for循環中正確部署gradecount計數器？

它應該在輸入每個年級後遞增。

for (int i = 0; i < numOfGrades; i++){ 
    double belowzero = gradeinput.nextDouble(); 
    int gradecount = 1; 
    System.out.println("enter grade number " + gradecount + ":"); 
    gradecount++; 

    while (belowzero < 0){ 
     belowzero = gradeinput.nextDouble(); 
    } 
    grades[i] = belowzero; 
} 
} 

Answer 1

在for循環之外初始化gradecount。

int gradecount = 1; 
for (int i = 0; i < numOfGrades; i++){ 
    double belowzero = gradeinput.nextDouble(); 

    System.out.println("enter grade number " + gradecount + ":"); 
    gradecount++; 

    while (belowzero < 0){ 
     belowzero = gradeinput.nextDouble(); 
    } 
    grades[i] = belowzero; 
} 
} 

Answer 2

我想gradecount跟蹤如何需要衆多的成績將被輸入。說他們需要進入4個年級，我只是想在顯示的是這樣一個gradecount添加「進入1級在這裏」，然後「進入2級在這裏」等

你並不需要一個gradecount您可以使用索引i來代替變量。

for (int i = 0; i < numOfGrades; i++){ 
     double belowzero = gradeinput.nextDouble(); 
     System.out.println("enter grade number " + (i+1) + ":"); 

     while (belowzero < 0){ 
      belowzero = gradeinput.nextDouble(); 
     } 
     grades[i] = belowzero; 
    }