參考資料：
GradeBook, GradeBookTest 兩個 class 分別存放在 GradeBook.java, GradeBookTest.java 檔
案中，且位於同一個目錄，下列部分題目必須參考這些程式碼。
1 //GradeBook.java 2 public class GradeBook 3 { 4 private String courseName; 5 private int[] grades; 6
7 public GradeBook( String name, int[] gradesArray ) 8 { 9 courseName = name;10 grades = gradesArray; 11 } 12 public void setCourseName( String name ) 13 { 14 courseName = name;
15 } 16 public String getCourseName() 17 { 18 return courseName;
19 } 20 public void displayMessage() 21 { 22 System.out.printf( "Welcome to the grade book for
%s!

", 23 getCourseName() ); 24 } 25 public void processGrades() 26 { 27 outputGrades(); 28 System.out.printf( "
Class average is %.2f
", getAverage() ); 29 //outputBarChart(); 30 } 31 public double getAverage() 32 { 33 int total = 0; // initialize total
34 for ( int grade : grades ) 35 total += grade; 36 return ( double ) total / grades.length; 37 } 38
39 //public void outputBarChart() 40
41 public void outputGrades() 42 { 43 System.out.println( "The grades are:
" ); 44 for ( int student = 0; student ＜ grades.length; student++ ) 45 System.out.printf( "Student %2d: %3d
", 46 student + 1, grades[ student ] ); 47 } 48 } 

1 // GradeBookTest.java 2 public class GradeBookTest 3 { 4 public static void main( String[] args ) 5 { 6
7 int[] gradesArray = { 87, 68, 94, 100, 83, 78, 85, 91, 76, 87 }; 8
9 GradeBook myGradeBook = new GradeBook( 10 "CS101 Introduction to Java Programming", gradesArray ); 11 myGradeBook.displayMessage(); 12 myGradeBook.processGrades(); 13 } 14 }

一、參考 GradeBook.java, GradeBookTest.java 檔案，試問 GradeBook 的建構子（Constructor）
在那裡？作用為何？（10 分）