Average Grade using If else..1 error please help

Question

Hi all..Okay I have to do this program that lets you input student info and 3 grades, figures out the average, and the letter grade using if else statements. I have only one error and cannot figure it out. Here is the error and a copy of my program. If someone can help me figure it out, I would appreciate it; I have tried everything I can think of. Thank you.
Error: Illegal start of expression for this line           {if (avg >=80)&&(avg <90)
Here is my program:
class my_main
     public static void main (String [] args) throws IOException
     String Name;
     String ID;
     double grade1;
     double grade2;
     double grade3;
     BufferedReader stdin;
     stdin= new BufferedReader (new InputStreamReader (System.in));
     System.out.println ("Please enter the following information: ");
     System.out.print ("Student Name: ");
     Name= stdin.readLine();
     System.out.print ("Student ID: ");
     ID= stdin.readLine();
     System.out.print ("Grade One: ");
     grade1= Double.parseDouble(stdin.readLine());
     System.out.print ("Grade Two: ");
     grade2= Double.parseDouble(stdin.readLine());
     System.out.print ("Grade Three: ");
     grade3=Double.parseDouble(stdin.readLine());
     gradebook pt= new gradebook (grade1, grade2, grade3, Name, ID);
     pt.display ();
class gradebook
     int LG;
     double gr1;
     double gr2;
     double gr3;
     double avg;
     String SName;
     String IDNO;
     public gradebook (double grade1, double grade2, double grade3, String Name, String ID) throws ArithmeticException
     gr1= grade1;
     gr2= grade2;
     gr3= grade3;
     IDNO=ID;
     SName=Name;
     avg=(gr1+gr2+gr3)/3;
          if (avg >= 90)
          LG='A';
          else
          {if (avg >=80)&&(avg <90)
             LG='B';
          else
          {if (avg >=70)&&(avg <80)
                   LG='C';
          else
          {if (avg >=60)&&(avg <70)
             LG='D';
          else
          {if (avg <= 59)
             LG='F';
     void display()
     System.out.println ("Student Grades for "+SName);
     System.out.println ("Student ID Number: "+IDNO);
     System.out.println ("Grade One: "+gr1);
     System.out.println ("Grade Two: "+gr2);
     System.out.println ("Grade Three: "+gr3);
     System.out.println ("Average: "+avg);
     System.out.println ("Letter Grade: "+LG);
}

Answer 1

Hi ,
There were some problems like you have defined any main method etc. I have corrected your code, and it is working....
Sandeep
* my_main.java
* Created on October 6, 2003, 12:53 PM
import java.io.*;
* @author sandeep
public class my_main {
public static void main(String args[]) throws IOException {
String Name;
String ID;
double grade1;
double grade2;
double grade3;
BufferedReader stdin;
stdin= new BufferedReader(new InputStreamReader(System.in));
System.out.println("Please enter the following information: ");
System.out.print("Student Name: ");
Name= stdin.readLine();
System.out.print("Student ID: ");
ID= stdin.readLine();
System.out.print("Grade One: ");
grade1= Double.parseDouble(stdin.readLine());
System.out.print("Grade Two: ");
grade2= Double.parseDouble(stdin.readLine());
System.out.print("Grade Three: ");
grade3=Double.parseDouble(stdin.readLine());
gradebook pt= new gradebook(grade1, grade2, grade3, Name, ID);
pt.display();
class gradebook {
int LG;
double gr1;
double gr2;
double gr3;
double avg;
String SName;
String IDNO;
public gradebook(double grade1, double grade2, double grade3, String Name, String ID) throws ArithmeticException {
gr1= grade1;
gr2= grade2;
gr3= grade3;
IDNO=ID;
SName=Name;
avg=(gr1+gr2+gr3)/3;
if (avg >= 90) {
LG='A';
} else if ((avg >=80)&&(avg <90)) {
LG='B';
} else if ((avg >=70)&&(avg <80)) {
LG='C';
} else if ((avg >=60)&&(avg <70)) {
LG='D';
} else if (avg <= 59) {
LG='F';
void display() {
System.out.println("Student Grades for "+SName);
System.out.println("Student ID Number: "+IDNO);
System.out.println("Grade One: "+gr1);
System.out.println("Grade Two: "+gr2);
System.out.println("Grade Three: "+gr3);
System.out.println("Average: "+avg);
System.out.println("Letter Grade: "+LG);