Thread: Fixing this grade finder program?

Okay im creating a program for my beginning programming class, and its one we get to make for personal use as well, so mine is a grade program!

In the loops i cant figure out how i can make it keep adding the stuff for example i run the program say there are 2 assignments first is worth 20 points second is worth 50 i cant figure out how to have it add them together and set my totalPoints as 70?

Next after it runs all of this i want it to tell me what i need on the assignments not done yet for each grade letter for example 4 assignments worth 25 a piece i want lets say if i got 20 20 20 on the first 3 i want it to tell me i need 0 points on assignment 4 for a D 10 for a C 20 for a B and that its impossible to get an A

Im just a little confused on what code i would need to do that and how i would have it do it for say multiple assignments, if i had 5 and had done 3 i want it to tell me the minimums on 4 and 5 without going over their maximum points, for example if 4 was worth 30 and 5 was worth 20 and i needed a total of 30 points i dont want it to say i need 30 on 4 and 0 on 5 i want it to say i need 15 each, and so on and so forth, im hoping this area doesnt get more complicated than i think it is in my head haha

import java.util.Scanner;
 
 
public class Prog5 {
 
	public static void main(String args[])
	{
		int numberOfGrades;
		int grades = 0;
		int gradesDone = 0;
		int completed;
		int totalPoints = 0;
		int points;
		int pointsEarned;
 
 
 
 
 
		Scanner input = new Scanner( System.in );
 
		System.out.println("How many total grades will there be? ");
		numberOfGrades = input.nextInt();
 
		do            
		{
		 grades++;
 
		System.out.println("Points possible for assignment " + grades + ":");
		points = input.nextInt();
 
 
 
		}while (grades < numberOfGrades);
 
		totalPoints = points;
 
		System.out.println("How many assignments completed?");
		completed = input.nextInt();
 
 
 
 
 
		do            
		{
		 gradesDone++;
 
		System.out.println("Points recieved on assignment " + gradesDone + ":");
		pointsEarned = input.nextInt();
 
 
 
		}while (gradesDone < completed);
 
		System.out.println(totalPoints);
		System.out.println(pointsEarned);
 
 
	}
}

Originally Posted by Norm

Look at using an array to hold the grades that are read in. After reading all the grades, you will be able to use a loop scan through the array and add them.

I had thought about arrays, but we never went to in depth in them besides literally just making one, and not sure what a loop scan is? sorry for my noobness! ill check the book see if i can figure out how to incorporate an array here

Originally Posted by Norm

I left out the word "to": use a loop to scan through the array.

So i know i would have to declare the array, then for length i would have to set it = the first integer input which is how many grades are there, How would i set the array then to be the numbers put in through that loop?

int [] grades = new int [numberOfGrades]; Correct for declaring?

Originally Posted by Norm

Have you passed that to the compiler? It will tell you if there are problems. I could miss something that the compiler wouldn't.

Well true, yes it doesnt have any errors, (using eclipse) but im not sure what i need to change up in that first loop to have it set the array to each of the numbers that i put in?

Originally Posted by Norm

You assign the value read in to a slot in the array at an index:
anArray[theIdx] = theValue;
then you increment the index so the next time the value will go into the next slot.
In a for loop, the for statement variable can be the index.

haha okay so as im understanding this which isnt very well this is the bit of code i have come up with

for (grade < grades.length; grade++ )
				totalPoints += grades [grade ];

But putting it in the while loop it wants me to create a class called grade (i have grade declared to = 0 )

what am i missing? this is turning into way more than i thought haha i didnt feel the array would be this complicated (to me at least)

Originally Posted by Norm

You need to see how to write a for loop:
The for Statement (The Java™ Tutorials > Learning the Java Language > Language Basics)

that was my bad on the loop i know for loops lol i just was taking something out of the book and left some stuff out, okay here is my first bit of code as of yet, when i run it and say i do 5 assignments and i put in 10 points for each assignment it says that = 60... can you tell what ive put in wrong for it to be adding it again??

import java.util.Scanner;
 
 
public class Prog5 {
 
	public static void main(String args[])
	{
		int numberOfGrades;
		int grade = 0; 
		int gradesDone = 0;
		int completed;
		int totalPoints = 0;
		int points;
		int pointsEarned;
 
 
 
 
 
		Scanner input = new Scanner( System.in );
 
		System.out.println("How many total grades will there be? ");
		numberOfGrades = input.nextInt();
 
		int [] grades = new int [numberOfGrades+1];
 
		do            
		{
 
		grade++;
		System.out.println("Points possible for assignment " + grade + ":");
		grades[grade] = input.nextInt();
 
 
 
		}while (grade < numberOfGrades);
 
		for (int counter = 0; counter < grades.length; counter++ )
			totalPoints += grades [grade]; 
 
		System.out.println(totalPoints);
 
}
}

Originally Posted by Norm

Print out the contents of the array so you can see what you are adding up. Use the Arrays class's toString method to format the array for printing:

System.out.println("an ID "+ java.util.Arrays.toString(theArrayName));

its doing everything like i want its setting the first array number to 0 then from there on out is right, its just adding them up very very weirdly?

Okay idk why it would do it but by changing counter =0 to =1 its doing it right now. So now on to the next task, im assuming my best bet is to set a second array the same way for the second loop for how many points i got on each assignment, so what is it that i will need to do after that to make my program figure out the points i need for each of the letter grades? im really not even sure where to start like i dont know what way i need to go about making A = 89.5-100 % of the points where i take the total points/ points ive gotten but printing out the points i need on the last assignments?


thats probably confusing lol its got me confused as well just looking for some tips, thank you, youve helped quite a bit already!

Originally Posted by Norm

I'm done for tonight. Back tomorrow.

alright thanks man! just messed up again tried different numbers and its still adding them up all weird.

Originally Posted by Norm

For testing reduce the size of the array to 3 and enter 3 different numbers like 1 22 55
then look at what the program prints out and see if there is something that stands out.

I actually got it working last night, i wasnt putting the counter in the places it needed to be! so here is my code working perfect up till this point, now just to figure out how to approach the next step, any tips?

import java.util.Scanner;
 
 
public class Prog5 {
 
	public static void main(String args[])
	{
		int numberOfGrades;
		int grade = 0; 
		int gradesDone = 0;
		int completed;
		int totalPoints = 0;
		int points;
		int pointsEarned = 0;
 
 
 
 
 
		Scanner input = new Scanner( System.in );
 
		System.out.println("How many total grades will there be? ");
		numberOfGrades = input.nextInt();
 
		int [] grades = new int [numberOfGrades+1];
 
		do            
		{
 
		grade++;
		System.out.println("Points possible for assignment " + grade + ":");
		grades[grade] = input.nextInt();
 
 
 
		}while (grade < numberOfGrades);
 
 
		for ( int counter=1; counter < grades.length; counter++ )
			totalPoints += grades[counter]; 
 
 
 
		System.out.println("an ID "+ java.util.Arrays.toString(grades));
 
		System.out.println(totalPoints);
 
		System.out.println("How many assignments completed?");
		completed = input.nextInt();
 
 
		int [] completedArray = new int [completed+1];
 
 
 
		do            
		{
		 gradesDone++;
 
		System.out.println("Points recieved on assignment " + gradesDone + ":");
		completedArray[gradesDone] = input.nextInt();
 
 
 
		}while (gradesDone < completed);
 
		for ( int counter=1; counter < completedArray.length; counter++ )
			pointsEarned += completedArray[counter]; 
 
		System.out.println(totalPoints);
		System.out.println(pointsEarned);
 
 
	}
}

Originally Posted by Norm

Sorry, I don't know what the next step is. Can you explain?

Sure, ill try and make it a little clearer basically after the input of the grades, i want it to then output saying what i need on the final grade and or grades at a minimum for each letter grade! For example lets say i had 4 total grades, each worth 25 points a piece and i got perfect on the first 2 and have 2 left! I want it to output saying for an A i need 20 on Assignment 3 and 20 on Assignment 4 For a B i need 15 on each then for a C 10 on each and D 5 on each, however i need to have stuff in there that spreads the points out like such and doesn't say 25 on one and 15 on one i want it spread as evenly as it can be, also if i had one assignment worth 5 and another worth 20 i dont want it to be like i need 10 and 10 when 5 is the max!

If that makes sense which i hope it does!

Well yeah, thats where im a little stumped i mean i have a formula to find how many grades are left, and how many points are left, but thats where im at i know the next thing i need to do is somehow make it where it adds points to each of the remaining grades without going over their maximum (id even be okay with if it added till the max on each one until it got to the point) until when you divide points earned + points added / total possible points is greater than or equal to .895 for an A that would at least get me started im just not sure what code i would put in to do that?

Originally Posted by Norm

Work on the steps to solve the problem first. When you have worked out the logic, THEN work on coding it.

Well i have the formulas for like i said the remaining grades, and remaining points!

lets say there are 4 assignments, done two 25 each and got 25 on each the last 2 are worth 25 each as well, My next bit needs to add onto the 3rd assignment and everytime it adds a point check the points earned/total points to verify it hasnt reached 89.5% yet and once it hits the max of that grade it then needs to move to assignment 4 and do the same thing until it reaches 89.5 when it does it will need to print

If thats what you mean by the logic im still fairly new at all this and some of it is just coming hard to me, like i understand what i need to do im just needing to figure out the direction in which i need to go for it