public?class?GradeBook?{
??private?String?courseName;
??public?GradeBook(String?name){
??????courseName?=name;??
??}
??public?void?setCourseName(String?name){
??????courseName=name;
??}
??public?String?getCourseName(){
??????return?courseName;
??}
??public?void?displayMessage(){
??????System.out.printf("welcome?to?the?grade?book?for\n%s!\n",getCourseName());
??}
}

上邊是同一個包里的????????GradeBook 類

下邊是同一個包里的??????? GradeBookTest 類

public?class?GradeBookTest?{
????public?static?void?main(String[]?args)
????{
????????GradeBook?gradeBook1=new?GradeBook("flying");
???????
????System.out.printf("gradeBook1?course?namm?is?%s\n",gradeBook1.getCourseName());
}
}

???GradeBook 類里邊 setCourseName 方法到底執(zhí)行了沒有？???GradeBookTest類里邊沒有見到另外誰能告訴我一下該代碼的執(zhí)行機理？多謝啦