package grade$\_$book$\_8$;

$//$ Fig. $7\mathrm{.}18$: GradeBook.java

$//$ Grade book using two$-$dimensional array to store grades.

public class GradeBook

$\{$

private String courseName; $//$ name of course this grade book represents

private int grades$[][]$; $//$ two$-$dimensional array of student grades

$//$ two$-$argument constructor initializes courseName and grades array

public GradeBook$($ String name, int gradesArray$[][])$

$\{$

courseName $=$ name; $//$ initialize courseName

grades $=$ gradesArray; $//$ store grades

$\}//$ end two$-$argument GradeBook constructor

$//$ method to set the course name

public void setCourseName$($ String name $)$

$\{$

courseName $=$ name; $//$ store the course name

$\}//$ end method setCourseName

$//$ method to retrieve the course name

$//$ method to retrieve the course name

public String getCourseName$()$

$\{$

return courseName;

$\}//$ end method getCourseName

$//$ display a welcome message to the GradeBook user

public void displayMessage$()$

$\{$

$//$ getCourseName gets the name of the course

System.out.printf$($ "Welcome to the grade book for

$\%$s$!$

$",$

getCourseName$())$;

$\}//$ end method displayMessage

$//$ perform various operations on the data

public void processGrades$()$

$\{$

$//$ output grades array

outputGrades$()$;

$//$ call methods getMinimum and getMaximum

System.out.printf$("$

$\%$s $\%$d

$\%$s $\%$d

$",$

"Lowest grade in the grade book is$",$ getMinimum$(),$

"Highest grade in the grade book is$",$ getMaximum$())$;

$//$ output grade distribution chart of all grades on all tests

outputBarChart$()$;

$\}//$ end method processGrades

$//$ find minimum grade

public int getMinimum$()$

$\{$

$//$ assume first element of grades array is smallest

int lowGrade $=$ grades$[0][0]$;

$//$ loop through rows of grades array

for $($ int studentGrades$[]$ : grades $)$

$\{$

$//$ loop through columns of current row

for $($ int grade : studentGrades $)$

$\{$

$//$ if grade less than lowGrade, assign it to lowGrade

if $($ grade $<$ lowGrade $)$

lowGrade $=$ grade;

$\}//$ end inner for

$\}//$ end outer for

return lowGrade; $//$ return lowest grade

$\}//$ end method getMinimum

$//$ find maximum grade

public int getMaximum$()$

$\{$

$//$ assume first element of grades array is largest

int highGrade $=$ grades$[0][0]$;

$//$ loop through rows of grades array

for $($ int studentGrades$[]$ : grades $)$

$\{$

$//$ loop through columns of current row

for $($ int grade : studentGrades $)$

$\{$

$//$ if grade greater than highGrade, assign it to highGrade

if $($ grade $>$ highGrade $)$

highGrade $=$ grade;

$\}//$ end inner for

$\}//$ end outer for

return highGrade; $//$ return highest grade

$\}//$ end method getMaximum

$//$ determine average grade for particular student $($or set of grades$)$

public double getAverage$($ int setOfGrades$[])$

$\{$

int total $=0$; $//$ initialize total

$//$ sum grades for one student

for $($ int grade : setOfGrades $)$

total $+=$ grade;

$//$ return average of grades

return $($double$)$ total $/$ setOfGrades.length;

$\}//$ end method getAverage

$//$ output bar chart displaying overall grade distribution

public void outputBarChart$()$

$\{$

System.out.println$($ "Overall grade distribution:" $)$;

$//$ stores frequency of grades in each range of $10$ grades

int frequency$[]=$ new int$[11]$;

$//$ for each grade in GradeBook, increment the appropriate frequency

for $($ int studentGrades$[]$ : grades $)$

$\{$

for $($ int grade : studentGrades $)$

$++$frequency$[$ grade $/10]$;

$\}//$ end outer for

$//$ for each grade frequency, print bar in chart

for $($ int count $=0$; count $<$ frequency.length; count$++)$

$\{$

$//$ output bar label $("00-09$: $",...,"90-99$: $","100$: $")$

if $($ count $==10)$

System.out.printf$("\%5$d: $",100)$;

else

System.out.printf$("\%02$d$-\%02$d: $",$

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

$\}//$ end method outputBarChart

$//$ output the contents of the grades array

public void outputGrades$()$

$\{$

System.out.println$($ "The grades are:

$")$;

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$/$columns of text representing array grades

for $($ int student $=0$; student $<$ grades.length; student$++)$

$\{$

System.out.printf$($ "Student $\%2$d$",$ student $+1)$;

for $($ int test : grades$[$ student $])//$ output student's grades

System.out.printf$("\%8$d$",$ test $)$;

$//$ call method getAverage to calculate student's average grade;

$//$ pass row of grades as the argument to getAverage

double average $=$ getAverage$($ grades$[$ student $])$;

System.out.printf$("\%9\mathrm{.}2$f

$",$ average $)$;

$\}//$ end outer for

$\}//$ end method outputGrades

$\}//$ end class GradeBook

package grade$\_$book$\_8$;

$//$ Fig. $7\mathrm{.}19$: GradeBookTest.java

$//$ Creates GradeBook object using a two