java code 在cmd上报了几个小错，高手进来看看

Question

import java.util.*;
class Student{
string name,sex,major;
int id;
Scanner in=new Scanner(System.in);
name=in.nextString();
sex=in.nextString();
id=in.nextInt();
major=in.nextString();
}
public class Course{
       string[] courses={"Java","English","SQL","Math","CAD","MVS.NET"}; 
       string[] course={"","","","","",""};    
         int i;
         int j=(int)(Math.random()*6);
       public void addCourse()
       { 
          for(i=0;i<j;i++)
          course[i]=courses[i];
       }        public void removeCourse()
         {for(i=0;i<j;i++)
             if(course[i]!="")
              course[i]="";
}
public void printStudentReport()
  { for(i=0;i<j;i++)  
     {System.out.println(course[i]);}
  }
public static void main(String[] args)
{ Student stu=new Student();
Course cours=new Course();
cours.addCourse();
cours.removeCourse();
}
}
cmd:
E:\Users\solitary\Documents\JAVA\java2\Student.java:6: 需要 <标识符>
        name=in.nextString();
            ^
E:\Users\solitary\Documents\JAVA\java2\Student.java:7: 需要 <标识符>
        sex=in.nextString();
           ^
E:\Users\solitary\Documents\JAVA\java2\Student.java:8: 需要 <标识符>
        id=in.nextInt();
          ^
E:\Users\solitary\Documents\JAVA\java2\Student.java:9: 需要 <标识符>
        major=in.nextString();
             ^
这几个变量我都声明了！为什么老报这几个错？

Answer 1

string name,sex,major; 
=》 String大写

Answer 2

name=in.nextString(); 
sex=in.nextString(); 
id=in.nextInt(); 
major=in.nextString(); 
改为
String name=in.nextString(); 
String sex=in.nextString(); 
String id=in.nextInt(); 
String major=in.nextString(); 
} 

Answer 3

import java.util.*; 
class Student{ 
String name,sex,major; 
int id; 
Scanner in=new Scanner(System.in); 
name=in.nextString(); 
sex=in.nextString(); 
id=in.nextInt(); 
major=in.nextString(); 
} 
public class Course{ 
      string[] courses={"Java","English","SQL","Math","CAD","MVS.NET"}; 
      string[] course={"","","","","",""};    
        int i; 
        int j=(int)(Math.random()*6); 
      public void addCourse() 
      { 
          for(i=0;i <j;i++) 
          course[i]=courses[i]; 
      }         public void removeCourse() 
        {for(i=0;i <j;i++) 
            if(course[i]!="") 
              course[i]=""; 
} 
public void printStudentReport() 
  { for(i=0;i <j;i++)  
    {System.out.println(course[i]);} 
  } 
public static void main(String[] args) 
{ Student stu=new Student(); 
Course cours=new Course(); 
cours.addCourse(); 
cours.removeCourse(); 
} 
}