Grade Calculator Alot of Errors While Compiling

[Canh Ly]

Hi I am writing a program that is designed to calculate your score in assignments, in class participation, labs, 2 midterms, and a final exam, I wrote the code to the best of my knowledge and upon review it looks like it should compile. When I compile, the errors I get are below. I only copied a few of the errors so you could get a better understanding. I attached the code that I wrote so far, and was wondering if anyone could help me understand my errors please with an explanation it would much appreciated.


GradesProgram4.java:38: non-static method getName() cannot be referenced from a static context
name = getName();
^
GradesProgram4.java:44: non-static method getName() cannot be referenced from a static context
ass6 = getName();
^
GradesProgram4.java:44: incompatible types
found : java.lang.String
required: int
ass6 = getName();
^
GradesProgram4.java:45: non-static method getName() cannot be referenced from a static context
ass7 = getName();
^
GradesProgram4.java:45: incompatible types
found : java.lang.String
required: int
ass7 = getName();

^
GradesProgram4.java:164: cannot find symbol
symbol : variable Keyboard
location: class GradesProgram4
int Inclass = Integer.parseInt(Keyboard.readLine());
^

39 errors

import java.io.*; public class GradesProgram5 { private static BufferedReader keyboard = new BufferedReader(new InputStreamReader(System.in)); [code=javascript]public static void main(String[] args) throws IOException{ //Section: Variables String name; int ass1 = 0; int ass2 = 0; int ass3 = 0; int ass4 = 0; int ass5 = 0; int ass6 = 0; int ass7 = 0; int ass8 = 0; //make sure there is a method for this int inclass = 0; int lab1 = 0; int lab2 = 0; int lab3 = 0; int lab4 = 0; int lab5 = 0; int lab6 = 0; int lab7 = 0; int lab8 = 0; int lab9 = 0; int lab10 = 0; int midTermExam1 = 0; int midTermExam2 = 0; int finalExam = 0; double finalScore = 0; char grade; //assigning methods name = getName(); ass1 = getAss1(); ass2 = getAss2(); ass3 = getAss3(); ass4 = getAss4(); ass5 = getAss5(); ass6 = getName(); ass7 = getName(); ass8 = getName(); inclass = getInclass(); lab1 = getLab1(); lab2 = getLab2(); lab3 = getLab3(); lab4 = getLab4(); lab5 = getLab5(); lab6 = getLab6(); lab7 = getLab7(); lab8 = getLab8(); lab9 = getLab9(); lab10 = getLab10(); //quiz1 = getFirstQuiz(); //quiz2 = getSecondQuiz(); midTermExam1 = getMidTermExam1(); midTermExam2 = getMidTermExam2(); finalExam = getFinalExam(); //put all variables into below finalScore = getScore(ass1, ass2, ass3, ass4, ass5, ass6, ass7, ass8, inclass, lab1, lab2, lab3, lab4, lab5, lab6, lab7, lab8, lab9, lab10, midTermExam1, midTermExam2, finalExam); grade = getLetterGrade(finalScore); System.out.println( "Student name: " + name ); System.out.println( "First assignment score: " + ass1 ); System.out.println( "Second assignment score: " + ass2 ); System.out.println( "Third assignment score: " + ass3 ); System.out.println( "Fourth assignment score: " + ass4 ); System.out.println( "Fifth assignment score: " + ass5 ); System.out.println( "Sixth assignment score: " + ass6 ); System.out.println( "Seventh assignment score: " + ass7 ); System.out.println( "Eighth assignment score: " + ass8 ); System.out.println( "First mid term score: " + midTermExam1 ); System.out.println( "Second mid term score: " + midTermExam2 ); System.out.println( "Final Exam score: " + finalExam ); System.out.println( "Your final score is: " + finalScore); System.out.println( "Your letter grade is: " + grade); }//End Method:main //Method:get grades private String getName() { System.out.println("Students calculated final scores"); System.out.println("and letter grades. "); System.out.println("Please enter your name. "); String name = keyboard.readLine(); return name; } private static int getAss1(){ System.out.println("Please enter an integer between 0-10 for your first assignment grade. "); int Ass1 = Integer.parseInt(Keyboard.readLine()); System.out.println("Your mark is " + Ass1); return Ass1; } private static int getAss2(){ System.out.println("Please enter an integer between 0-10 for your second assignment grade. "); int Ass2 = Integer.parseInt(Keyboard.readLine()); System.out.println("Your mark is " + Ass2); return Ass2; } private static int getAss3(){ System.out.println("Please enter an integer between 0-10 for your third assignment grade. "); int Ass3 = Integer.parseInt(Keyboard.readLine()); System.out.println("Your mark is " + Ass3); return Ass3; } private static int getAss4(){ System.out.println("Please enter an integer between 0-10 for your fourth assignment grade. "); int Ass4 = Integer.parseInt(Keyboard.readLine()); System.out.println("Your mark is " + Ass4); return Ass4; } private static int getAss5(){ System.out.println("Please enter an integer between 0-10 for your fifth assignment grade. "); int Ass5 = Integer.parseInt(Keyboard.readLine()); System.out.println("Your mark is " + Ass5); return Ass5; } private static int getAss6(){ System.out.println("Please enter an integer between 0-10 for your sixth assignment grade. "); int Ass6 = Integer.parseInt(Keyboard.readLine()); System.out.println("Your mark is " + Ass6); return Ass6; } private static int getAss7(){ System.out.println("Please enter an integer between 0-10 for your seventh assignment grade. "); int Ass7 = Integer.parseInt(Keyboard.readLine()); System.out.println("Your mark is " + Ass7); return Ass7; } private static int getAss8(){ System.out.println( "Please enter an integer between 0-10 for your eighth assignment grade. "); int Ass8 = Integer.parseInt(Keyboard.readLine()); System.out.println("Your mark is " + Ass8); return Ass8; } private static int getInclass(){ //remember to change quiz for InClass System.out.println("Please enter an integer between 0-6 for class participation. "); int Inclass = Integer.parseInt(Keyboard.readLine()); System.out.println("Your mark is " + Inclass); return Inclass; } private static int getLab1(){ System.out.println("Enter integer 0 or 1 for Lab1 mark. "); int Lab1 = Integer.parseInt(Keyboard.readLine()); System.out.println("Your mark is " + Lab1); return Lab1; } private static int getLab2(){ System.out.println("Enter integer 0 or 1 for Lab2 mark. "); int Lab2 = Integer.parseInt(Keyboard.readLine()); System.out.println("Your mark is " + Lab2); return Lab2; } private static int getLab3(){ System.out.println("Enter integer 0 or 1 for Lab3 mark. "); int Lab3 = Integer.parseInt(Keyboard.readLine()); System.out.println("Your mark is " + Lab3); return Lab3; } private static int getLab4(){ System.out.println("Enter integer 0 or 1 for Lab4 mark. "); int Lab4 = Integer.parseInt(Keyboard.readLine()); System.out.println("Your mark is " + Lab4); return Lab4; } private static int getLab5(){ System.out.println("Enter integer 0 or 1 for Lab5 mark. "); int Lab5 = Integer.parseInt(Keyboard.readLine()); System.out.println("Your mark is " + Lab5); return Lab5; } private static int getLab6(){ System.out.println("Enter integer 0 or 1 for Lab6 mark. "); int Lab6 = Integer.parseInt(Keyboard.readLine()); System.out.println("Your mark is " + Lab6); return Lab6; } private static int getLab7(){ System.out.println("Enter integer 0 or 1 for Lab7 mark. "); int Lab7 = Integer.parseInt(Keyboard.readLine()); System.out.println("Your mark is " + Lab7); return Lab7; } private static int getLab8(){ System.out.println("Enter integer 0 or 1 for Lab8 mark. "); int Lab8 = Integer.parseInt(Keyboard.readLine()); System.out.println("Your mark is " + Lab8); return Lab8; } private static int getLab9(){ System.out.println("Enter integer 0 or 1 for Lab9 mark. "); int Lab9 = Integer.parseInt(Keyboard.readLine()); System.out.println("Your mark is " + Lab9); return Lab9; } private static int getLab10(){ System.out.println("Enter integer 0 or 1 for Lab10 mark. "); int Lab10 = Integer.parseInt(Keyboard.readLine()); System.out.println("Your mark is " + Lab10); return Lab10; } //Method: get Mid Term Exam marks private static int getMidTermExam1() { System.out.println("Please enter your midterm1 exam grade. "); int midTermExam1 = Integer.parseInt(keyboard.readLine()); return midTermExam1; } private static int getMidTermExam2() { System.out.println("Please enter your midterm2 exam grade. "); int midTermExam2 = Integer.parseInt(keyboard.readLine()); return midTermExam2; } //Method: get Final Exam private static int getFinalExam() { System.out.println("Please enter your finalexam grade. "); int finalExam = Integer.parseInt(keyboard.readLine()); return finalExam; } //Method: Calculate Score private static double getScore(int ass1, int ass2, int ass3, int ass4, int ass5, int ass6, int ass7, int ass8, int inclass, int lab1, int lab2, int lab3, int lab4, int lab5, int lab6, int lab7, int lab8, int lab9, int lab10, int midTermExam1, int midTermExam2, int finalExam) { //labs labs/10*.10 double tass = ((ass1 + ass2 + ass3 + ass4 + ass5 + ass6 + ass7 + ass8)/80*.24); double tinclass = (((inclass)/10)*.06); double tlabs = ((lab1 + lab2 + lab3 + lab4 + lab5 + lab6 + lab7 + lab8 + lab9 + lab10)/10*.10); double tMidTerm = ((midTermExam1 + midTermExam2/100)*.20); double tFinal = ((finalExam/100)*.40); double finalScore = tAss +tInclass +tLabs + tMidTerm + tFinal; return finalScore; } //Method: get letter grade private static char getLetterGrade(double finalScore){ String grade; if (score >=96.5) { grade = "A+"; System.out.println(" Grade = A+"); } else if (score >=92.5) { grade = "A"; System.out.println(" Grade = A"); } else if (score >=87.5) { grade = "A-"; System.out.println(" Grade = A-"); } else if (score >=82.5) { grade = "B+"; System.out.println(" Grade = B+"); } else if (score >=77.5) { grade = "B"; System.out.println(" Grade = B"); } else if (score >=71.5) { grade = "B-"; System.out.println(" Grade = B-"); } else if (score >=65.5) { grade = "C+"; System.out.println(" Grade = C+"); } else if (score >=59.5) { grade = "C"; System.out.println(" Grade = C"); } else if (score >=49.5) { grade = "D"; System.out.println(" Grade = D"); } else { // score < 49.4 grade = "F"; System.out.println(" Grade = F"); } } }//End Class: gradesProgram

[Gaurangkumar Khalasi]

 

Canh Ly wrote:
GradesProgram4.java:38: non-static method getName() cannot be referenced from a static context
name = getName();
^

GradesProgram4.java:44: non-static method getName() cannot be referenced from a static context
ass6 = getName();
^
GradesProgram4.java:45: non-static method getName() cannot be referenced from a static context
ass7 = getName();
^

From the static method (i.e. main()), you can call only static members(Both methods and/or variables) but not non-static members(in your case getName() is a non-static).

Reason: Because non-static members are the instance variables. They are attached with Object (and not with Class).
If you want to use them than you have to create an object of the class and than you can do it.

Canh Ly wrote:
GradesProgram4.java:44: incompatible types
found : java.lang.String
required: int
ass6 = getName();
^

GradesProgram4.java:45: incompatible types
found : java.lang.String
required: int
ass7 = getName();

^

The above errors are easily understood. You can also do it yourself.
You are trying to assign String value(will get from getName() method) to integer variables(ass6 & ass7).

Canh Ly wrote:
GradesProgram4.java:164: cannot find symbol
symbol : variable Keyboard
location: class GradesProgram4
int Inclass = Integer.parseInt(Keyboard.readLine());
^

Here it is a spelling mistake. You have written 'Keyboard' rather than 'keyboard'(See line no 04).

[Canh Ly]

Im still having trouble understanding what to do, so when I am trying to assign a string a value it isn't what I'm supposed to do? I thought that if you do that it will retrieve what the user put in and save it so it can be called to the print? I dont know how to switch the static and non, is that where I have to put on a line Static and void?

[Winston Gutkowski]

 

Canh Ly wrote:I attached the code that I wrote so far...

Canh,

I've broken up those enormous lines in your code. They screw up the windowing for your thread.
Please DON'T use lines more than about 100 characters long inside code blocks (I suggest you read the UseCodeTags page again. Thoroughly.)

Thanks

Winston

[Matthew Brown]

Hi Canh. Welcome to the Ranch!

You really shouldn't ever reach anywhere near this number of compiler errors. Compile early and compile often: write a few lines at a time, and compile. Fix problems as they arrive. If you write this much code before trying to compile it you're going to enter a world of pain - there are clearly some fundamental areas of Java you don't understand, and with this many errors you're just going to get lost.

So I'd actually recommend starting again. Write a new class that just contains an empty main method. Compile it. If it's OK, add two or three lines. Compile them. Continue like this.

To focus on one of your problems: the incompatible types. Java is strongly typed. That means that you need to decide what data type each variable will hold, and each method will return. And the compiler will then make sure you never assign the wrong type.

For example, you declare ass6 to hold int values like like this:

int ass6 = 0;

You then declare getName to return a String like this:

private String getName()

And then you try to assign the result of a getName() call to ass6 (and the compiler helpfully tells you where the problem is):

ass6 = getName();

That means you're trying to assign a String value to an int variable. Either the variable really ought to be a String, or you need to convert from a String to an int. There's a method in the Integer class that can do this (although it seems unlikely that a "name" is really a number, so that's probably not what you need here).

With respect to the static/non-static confusion, I think you need to go away and review how objects work in Java. This is particularly true because you're currently trying to write your code in a procedural way. Java is an object-oriented language, and a well-designed Java program has to take notice of this. The Java tutorials at http://docs.oracle.com/javase/tutorial/java/javaOO/index.html would be a good place to start.

[Greg Ferguson]

Hi Canh,

That is an insane amount of code you got there. For what you're trying to accomplish, I would do some research on using arrays. That way you could cut this:

int ass1 = 0;
int ass2 = 0;
int ass3 = 0;
int ass4 = 0;
int ass5 = 0;
int ass6 = 0;
int ass7 = 0;
int ass8 = 0;

down to something like this:

int assignments[] = new int[8];

Then you could do something similar to this:

double sum = 0;
for (int i = 0; i < assignments.length; i++)
{
double total = Double.parseDouble(grades[i]);
sum += total;
}
System.out.println("Your total is: " + total);

And you can learn to cut down all of your redundant code to just a couple of methods like this:

public static void getAssignments(String m, int a) throws NumberFormatException, IOException
{
System.out.println(m);
int b = Integer.parseInt(keyboard.readLine());
System.out.println("Your mark is " + b);
}
public static void getLabs(String m, int a) throws NumberFormatException, IOException
{
// Code for labs here
}

Learn to create classes and store relevant methods in them and then call what you need from the class that contains your main() method; it will make things a lot cleaner. And just one more nitpick, use lowercase or camelcase (ex. int getGrades) lettering for variable and methods. Otherwise you end up with mistakes like creating the variable keyboard and trying to use Keyboard -- which doesn't exist.
And to quote what Matthew said:

Compile early and compile often: write a few lines at a time, and compile. Fix problems as they arrive. If you write this much code before trying to compile it you're going to enter a world of pain

is some really good advice. Best wishes.

[fred rosenberger]

Go back to the version you have that give you no compiler errors. Only add 2-3 lines at a time before you re-compile.

What's that? You don't have any previous versions? Then start from scratch.

Seriously.

writing 300+ lines of code and only THEN trying to get it to compile is going to be nothing but pain and agony. You would seriously do better to start over.

[Steven Bruton]

Its obvious he did not write this code, its clearly some sort of debugging exercise for homework. If he had enough knowledge to write this code he could not possibly have a problem debugging these simple errors (eclipse suggests fixes for most of them).

Look at the error on line 6...
Line 6: " [code=javascript]public static void main(String[] args) throws IOException{"

[Canh Ly]

 

Steven Bruton wrote:Its obvious he did not write this code, its clearly some sort of debugging exercise for homework. If he had enough knowledge to write this code he could not possibly have a problem debugging these simple errors (eclipse suggests fixes for most of them).

Look at the error on line 6...
Line 6: " [code=javascript]public static void main(String[] args) throws IOException{"

Hi, I did in fact write the code, I've been watching videos and getting examples from other people in order to write the code that I had. After reading the replies, I defiantly know how to fix the redundancy of my code with for loops which I have failed to put in. Thanks for all the help though, I'm going to have to rewrite it with a skeleton now and hope for the best.