吧里有java的老哥吗，一个很小的问题

饶老师教你截图

图片最下面红字提示的就是我打的那个主方法定义……

放到类里面就行了

在wp7吧你甚至可以套路代码

package ch53;
public class GradeBook {
private String courseName;
private int grades[][];
public GradeBook(String name,int gradesArray[][]) {
courseName=name;
grades=gradesArray;
}
public void setCourseName(String name) {
courseName=name;
}
public String getCoursetName() {
return courseName;
}
public void displayMessage() {
System.out.printf("Welcome to the grade book for\n%s!\n\n",getCoursetName());
}
public void processGrades() {
outputGrades();
System.out.printf("\n%s %d\n%s %d\n\n","the lowest grade in the grade book is",getMinimum(),
"the highest grade in the grade book is",getMaximum());
outputBarChart();
}
public int getMinimum() {
int lowGrade=grades[0][0];
for(int studentGrades[]:grades)
{
for(int grade:studentGrades)
{
if(grade<lowGrade)
lowGrade=grade;
}
}
return lowGrade;
}
public int getMaximum() {
int highGrade=grades[0][0];
for(int studentGrades[]:grades)
{
for(int grade:studentGrades)
{
if(grade>highGrade)
highGrade=grade;
}
}
return highGrade;
}
public double getAverage(int setOfGrades[]) {
int total=0;
for(int grade:setOfGrades)
total+=grade;
return(double)total/setOfGrades.length;
}
public void outputBarChart() {
System.out.println("Overall grade distribution:");
int frequency[]=new int[11];
for(int studentGrades[]:grades) {
for(int grade:studentGrades)
++frequency[grade/10];
}
for(int count=0;count<frequency.length;count++)
{
if(count==10)
System.out.printf("%5d:",100);
else
System.out.printf("%02d-%02d:",
count*10,count*10+9);
for(int stars=0;stars<frequency[count];stars++)
System.out.print("*");
System.out.println();
}
}
public void outputGrades() {
System.out.println("The grades are:\n");
System.out.print(" ");
for(int test=0;test<grades[0].length;test++)
System.out.printf("Test %d ",test+1);
System.out.println("Average");
for (int student=0;student<grades.length;student++)
{
System.out.printf("Student %2d",student=1);
for(int test:grades[student])
System.out.printf("%8d",test);
double average=getAverage(grades[student]);
System.out.printf("%9.2f\n",average);
}
}
}

给第6和第7行，中间加入代码，public statis void main（String[] args）{}

static手滑打错了

创建的时候打个勾不就行了

main方法是入口，程序执行的是main方法

没有main()方法你让jvm从哪开始执行

你没写主函数啊，主方法放到最后一个 } 之前，就是包含在GradeBook中，然后在主方法中调用你自己写的方法。现在你只是定义了方法还没有调用

从main方法开始执行