Need help with Java Grades. (While Loop String input)

[Energizer100]

Hey. I'm new to Java and I'm trying to make a grades program for a class assignment. This is what I have so far.

import java.util.Scanner;
import static java.lang.System.out;
 
public class Grades//Creates Class
{
    public static void main(String[] args)
    {
        Scanner myScanner = new Scanner(System.in);
        String grade;
        double counter1 = 0.0;//Variables
        double counter2 = 0.0;
        char i;        
        char F;
 
        out.println("Enter your grade: ");
        grade = myScanner.nextLine();
 
        while(grade != "q"){
 
        out.println("Enter your grade. Enter q to see whether or not you are eligible: ");
        grade = myScanner.nextLine();
 
        if (grade == "A")
         {
            counter1 += 4.0;
            counter2++;
         }
        else if (grade == "B")
         {
            counter1 += 3.0;
            counter2++;
         }
        else if (grade == "C")
         {
            counter1 += 2.0;
            counter2++;
         }
        else if (grade == "D")
         {
            counter1 += 1.0;
            counter2++;
         }
        else if (grade == "F")
         {
            i = 'F';
            counter1 += 0.0;
            counter2++;
          }
 
         }
 
        if (grade == "q"){
 
        if (counter2 < 4){
            System.out.println("Ineligible, taking less than 4 classes");
         }
        else if ((counter2 >= 4) && (counter1/counter2 < 2.0)){
            System.out.println("Ineligible, gpa below 2.0");
         }
        else if (i == 'F')
        {
            if ((counter2 >= 4) && (counter1 / counter2 < 2.0)){
                System.out.println("Inelegible, gpa below 2.0 and has F grade");
            }
            else ((counter2 >= 4) && (counter1 / counter2 >= 2.0)){
                System.out.println("Inelegible, gpa above 2.0 but has F grade");
            }
        }
 
        else{
            System.out.println("GPA = " + (counter1/counter2) + " Eligible");
         }
        }
   }    
       }

It says stuff like 'i' is not initialized. But when I delete that line of code(I need it there though, just testing it), the string input thing won't stop when I enter q.

[Dameon99]

Hey. I'm new to Java and I'm trying to make a grades program for a class assignment. This is what I have so far.


import java.util.Scanner;
import static java.lang.System.out;

public class Grades//Creates Class
{
public static void main(String[] args)
{
Scanner myScanner = new Scanner(System.in);
String grade;
double counter1 = 0.0;//Variables
double counter2 = 0.0;
char i;
char F;

out.println("Enter your grade: ");
grade = myScanner.nextLine();

while(grade != "q"){

out.println("Enter your grade. Enter q to see whether or not you are eligible: ");
grade = myScanner.nextLine();

if (grade == "A")
{
counter1 += 4.0;
counter2++;
}
else if (grade == "B")
{
counter1 += 3.0;
counter2++;
}
else if (grade == "C")
{
counter1 += 2.0;
counter2++;
}
else if (grade == "D")
{
counter1 += 1.0;
counter2++;
}
else if (grade == "F")
{
i = 'F';
counter1 += 0.0;
counter2++;
}

}

if (grade == "q"){

if (counter2 < 4){
System.out.println("Ineligible, taking less than 4 classes");
}
else if ((counter2 >= 4) && (counter1/counter2 < 2.0)){
System.out.println("Ineligible, gpa below 2.0");
}
else if (i == 'F')
{
if ((counter2 >= 4) && (counter1 / counter2 < 2.0)){
System.out.println("Inelegible, gpa below 2.0 and has F grade");
}
else ((counter2 >= 4) && (counter1 / counter2 >= 2.0)){
System.out.println("Inelegible, gpa above 2.0 but has F grade");
}
}

else{
System.out.println("GPA = " + (counter1/counter2) + " Eligible");
}
}
}
}



It says stuff like 'i' is not initialized. But when I delete that line of code(I need it there though, just testing it), the string input thing won't stop when I enter q.

All variables should be initialised when you decalare them.

ie int i = 0;

i will be changed later in your code but this would initialise the variable and keep your compiler happy :-)

[Energizer100]

All variables should be initialised when you decalare them.

ie int i = 0;

i will be changed later in your code but this would initialise the variable and keep your compiler happy :-)

Ah, I see now.

I'm also making another grades program, but it has a do while loop and a while loop. But I'm having problems with 'i'. See, when the loop runs, and the user enters 'i', I want 'i' to store the value 'F'. So in my while loop, if 'i' was equal to 'F', it would go to a different if-else statement.


import java.io.*;

public class Grade 
{
    public static void main(String[] args) throws IOException 
    {
      BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
      String inData;
      double grade = 0;
      double counter1 = 0.0;
 
      do
      {
        System.out.println("Enter your grade. Enter q to quit");
        inData = br.readLine();
 
         if (inData.equals("A"))
         {
           grade = grade + 4.0;
           counter1++;
         } 
         else if (inData.equals("B"))
         {
           grade = grade + 3.0;
           counter1++;
         }
         else if (inData.equals("C"))
         {
              grade = grade + 2.0;
              counter1++;
         }
         else if (inData.equals("D"))
         {
           grade = grade + 1.0;
           counter1++;
         }
         else if (inData.equals("F"))
         {
           grade = grade + 0.0;
           counter1++;
         }      
    }
 
    while  (!inData.equals("q"));{
 
        if (counter1 < 4){
            System.out.println("Ineligible, taking less than 4 classes");
         }
        else if ((counter1 >= 4) && (grade / counter1 < 2.0)){
            System.out.println("Ineligible, gpa below 2.0");
         }
 
        else{
            System.out.println("GPA = " + (grade/counter1) + " Eligible");
         }    
        }
}
}

[Energizer100]

Ah, I see now.

I'm also making another grades program, but it has a do while loop and a while loop. But I'm having problems with 'i'. See, when the loop runs, and the user enters 'i', I want 'i' to store the value 'F'. So in my while loop, if 'i' was equal to 'F', it would go to a different if-else statement.


import java.io.*;

public class Grade
{
public static void main(String[] args) throws IOException
{
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
String inData;
double grade = 0;
double counter1 = 0.0;

do
{
System.out.println("Enter your grade. Enter q to quit");
inData = br.readLine();

if (inData.equals("A"))
{
grade = grade + 4.0;
counter1++;
}
else if (inData.equals("B"))
{
grade = grade + 3.0;
counter1++;
}
else if (inData.equals("C"))
{
grade = grade + 2.0;
counter1++;
}
else if (inData.equals("D"))
{
grade = grade + 1.0;
counter1++;
}
else if (inData.equals("F"))
{
grade = grade + 0.0;
counter1++;
}
}

while (!inData.equals("q"));{

if (counter1 < 4){
System.out.println("Ineligible, taking less than 4 classes");
}
else if ((counter1 >= 4) && (grade / counter1 < 2.0)){
System.out.println("Ineligible, gpa below 2.0");
}

else{
System.out.println("GPA = " + (grade/counter1) + " Eligible");
}
}
}
}

nvr mind. I found out the reason. Thank you so much for the help.