Java数组显示被缩短

Question

我输入了一个Java程序，该程序可以为学生计算成绩数组。 问题在于，只有一个数据集被打印到屏幕上，即学生10的成绩。我正在寻找所有学生的所有成绩。

知道有什么办法可以解决吗？

这是代码：

 public class SummariseGrades
 {
 public static void main (String[]args)
 {
    //2d array of student grades
    int [][] gradesArray =
    { { 87,96,70 },
      { 68,87,90 },
      { 94,100,90 },
      { 100,81,82},
      { 83,65,85},
      { 78,87,85},
      { 85,75,83},
      { 91,94,100},
      { 76,72,84},
      { 87,93,73}  };

    //output grades array
    outputGrades ( gradesArray );

    //call methods getMinimum and getMaximum
    System.out.printf ("\n %s %d \n %s %d \n \n",
    "Lowest grade is", getMinimum ( gradesArray ),
    "Highest grade is", getMaximum (gradesArray ) ) ;

    //output grade distribution chart of all grades on all tests
    outputBarChart (gradesArray);

} //end main





//find minimum grade
public static int getMinimum (int grades [][])
{
    //assume first element of grades array is the minumum
    int lowGrade = grades [0][0];

    //loop through rows of grades array
    for (int [] studentGrades : grades )
    {
        //loop throught the columns of current row
        for (int grade : studentGrades )
        {
            //if grade less than lowGrade, assign it to lowGrade
            if (grade < lowGrade)
            lowGrade = grade ;
        } //end inner
    }//end outer

    return lowGrade;  // returns lowest grade
} //end method getMinimum





//find maximum grade
public static int getMaximum (int grades [][])
{
    //assume first element is the largest in array
    int highGrade = grades [0][0];

    //loop through rows of the grades array
    for (int[] studentGrades : grades)
    {
        //loop through columns of the current row
        for (int grade: studentGrades)
        {
            //if grade greater than highGrade then assign it to highGrade
            if (grade > highGrade)
            highGrade = grade;
        } //end inner
    } //end outer

    return highGrade;  // return highest grade

} //end method getMaximum



//determine average grade for particular set of grades
public static double getAverage (int[] setOfGrades )
{
    int total = 0;  // initialise total

    //sum grades for one student
    for (int grade : setOfGrades)
    total += grade;

    //return average of grades
    return (double) total / setOfGrades.length;
} //end method for getAverage



//output bar chart displaying overall grade distribution
public static void outputBarChart (int grades[][])
{
    System.out.println ("Overall grade distribution:");

    //stores the frequency of grades in each range of 10 grades
    int[] frequency = new int [11];

    // for each grade in the grade book, increment the appropriate frequency
    for (int [] studentGrades : grades)
    {
        for (int grade : studentGrades)
        ++frequency [ grade / 10 ];
    } //end outer

    //for each grade freq, print bar in chart
    for (int count = 0 ; count < frequency.length ; count++)
    {
        //output bar label
        if (count ==10)
        System.out.printf ( "%5d: ", 100);

        else
            System.out.printf ("%02d-%02d: ",
            count * 10, count * 10 + 9 );

        //print bar of asterisks
        for (int stars = 0 ; stars < frequency [ count ] ; stars++)
            System.out.print ("*");

        System.out.println();  //start a new line of output

    } //end outer for loop

} //end method for outputBarChart



//output contents of the grades array

public static void outputGrades ( int grades [][])
{
    System.out.println ("The grades are:\n");
    System.out.print ("               "); //align column heads

    // create a column heading for each of the tests
    for (int test = 0 ; test < grades [0].length; test ++)
        System.out.printf ("Test %d ", test + 1);

        System.out.println ("Average");  //student average column heading

    //create rows and columns of text representing array grades

  for (int student = 0 ; student < grades.length ; student ++)
  {
    System.out.printf ("Student %2d", student + 1);

    for ( int test : grades [ student ] ) // output student grades
        System.out.printf ("%8d", test );

    // call method getAverage to calculate the student's average grade
    // pass row of grades as the argument to getAverage
    double average = getAverage (grades [ student ] ) ;
    System.out.printf ("%9.2f \r", average );

    } // end outer for
 } // end method outputGrades
} // end class Summerise Grades

Answer 1

甚至我都可以重现此错误。 问题出在printf 。 像这样编辑代码，即使在文本板中也可以使用

for (int student = 0 ; student < grades.length ; student ++)
{
System.out.printf ("Student %2d", student + 1);

for ( int test : grades [ student ] ) // output student grades
    System.out.printf ("%8d", test );

// call method getAverage to calculate the student's average grade
// pass row of grades as the argument to getAverage
double average = getAverage (grades [ student ] ) ;
System.out.printf ("%9.2f \r", average );



/*Add this line */ 


       System.out.println ("");



} // end outer for

要么

正如汤姆建议的

for (int student = 0 ; student < grades.length ; student ++)
{
System.out.printf ("Student %2d", student + 1);

for ( int test : grades [ student ] ) // output student grades
    System.out.printf ("%8d", test );

// call method getAverage to calculate the student's average grade
// pass row of grades as the argument to getAverage
double average = getAverage (grades [ student ] ) ;

/* change this line */


System.out.printf ("%9.2f \n", average );



} // end outer for

供您参考

之前：

bhargav@bhargav:~$ javac SummariseGrades.java 
bhargav@bhargav:~$ java SummariseGrades 
The grades are:

               Test 1 Test 2 Test 3 Average
Student 10      87      93      73    84.33 
 Lowest grade is 65 
 Highest grade is 100 

Overall grade distribution:
00-09: 
10-19: 
20-29: 
30-39: 
40-49: 
50-59: 
60-69: **
70-79: ******
80-89: ************
90-99: *******
  100: ***

之后：

bhargav@bhargav:~$ javac SummariseGrades.java 
bhargav@bhargav:~$ java SummariseGrades 
The grades are:

               Test 1 Test 2 Test 3 Average
Student  1      87      96      70    84.33 
Student  2      68      87      90    81.67 
Student  3      94     100      90    94.67 
Student  4     100      81      82    87.67 
Student  5      83      65      85    77.67 
Student  6      78      87      85    83.33 
Student  7      85      75      83    81.00 
Student  8      91      94     100    95.00 
Student  9      76      72      84    77.33 
Student 10      87      93      73    84.33 

 Lowest grade is 65 
 Highest grade is 100 

Overall grade distribution:
00-09: 
10-19: 
20-29: 
30-39: 
40-49: 
50-59: 
60-69: **
70-79: ******
80-89: ************
90-99: *******
  100: ***

Answer 2

我测试了您的代码并获得以下输出：

The grades are:

           Test 1 Test 2 Test 3 Average
Student  1      87      96      70    84.33 
Student  2      68      87      90    81.67 
Student  3      94     100      90    94.67 
Student  4     100      81      82    87.67 
Student  5      83      65      85    77.67 
Student  6      78      87      85    83.33 
Student  7      85      75      83    81.00 
Student  8      91      94     100    95.00 
Student  9      76      72      84    77.33 
Student 10      87      93      73    84.33 
Lowest grade is 65 
Highest grade is 100 

Overall grade distribution:
00-09: 
10-19: 
20-29: 
30-39: 
40-49: 
50-59: 
60-69: **
70-79: ******
80-89: ************
90-99: *******
100: ***

这是您想要的结果吗？