math program help..

[Jeremy Parsons]

I have this project I need help with.. I am supposed to creat a simple math quiz/test and it will ask five questions each with four multiple choice answers..

The program needs to tell whether they are correct or incorrect for each answer, as well as display the correct answer if wrong.. It will also need to calculate the total percentage of correct answers at the end of the program..

I am listing what I have made so far, and wanted to know if something looks wrong here..

  public class MathTest
{
 
public static void main(String[]args) throws Exception
{
 
char q1,q2,q3,q4,q5;
char a1 = 'c';
 

System.out.println("1. 7 + 2 = ?  a.6 b.8 c.9 d.10");
System.out.print("Enter your answer: ");
q1 = System.in.read();System.in.read();System.in.read();
 
if (q1 == 'c')
if (q2 == 'c')
if (q3 == 'b')
if (q4 == 'c')
if (q5 == 'd')
System.out.println("Correct!");
 
else
System.out.println("Sorry! The correct answer is: " +a1);
 

 
}
}  

Any help is greatly appreciated...

[Scott Johnson]

wanted to know if something looks wrong here

Yes, there are a few issues here.

I think you'll find many people willing to help, but unwilling to give you the solution.

I suggest asking a specific question. You'll get a specific answer that will get you closer to your goal.

It may be easier if you write your logic as psuedocode. For example:

public class Widget
{
    // display message
 
    // accept input
 
    // do calculation
 
    // print result
 

}
 

That might allow you to focus on the logical steps without worrying about Java syntax. Once you've got the psuedocode correct, you can fill in around the comments with real code.

[Jeremy Parsons]

I'm trying to compile and am getting 'else' without 'if' errors..
Here's the new code I am trying to compile..

  
public class MathTest
{
 
public static void main(String[]args) throws Exception
{
 
int a1,a2,a3,a4,a5;
 

// Question #1
System.out.println("1. 7 + 2 = ?  a.6  b.8  c.9  d.10");
System.out.print("Enter your answer: ");
a1 = System.in.read();System.in.read();System.in.read();
 
if (a1 == 'c')
 
System.out.println("Correct!");
System.out.println();
else
System.out.println("Sorry! The correct answer is c");
System.out.println();
 
//Question #2
System.out.println("2. 9 - 5 = ?  a.2  b.4  c.6  d.8");
System.out.print("Enter your answer: ");
a2 = System.in.read();System.in.read();System.in.read();
 
if (a2 == 'b')
 
System.out.println("Correct!");
System.out.println();
else
System.out.println("Sorry! The correct answer is b");
System.out.println();
 
//Question #3
System.out.println("3. 144/12 = ?  a.10  b.12  c.14  d.16");
System.out.print("Enter your answer: ");
a2 = System.in.read();System.in.read();System.in.read();
 
if (a3 == 'b')
 
 System.out.println("Correct!");
System.out.println();
else
System.out.println("Sorry! The correct answer is b");
System.out.println();
 
//Question #4
System.out.println("4. 5 * 5 = ?  a.10  b.20  c.25  d.125");
System.out.print("Enter your answer: ");
a2 = System.in.read();System.in.read();System.in.read();
 
if (a4 == 'c')
 
System.out.println("Correct!");
System.out.println();
else
System.out.println("Sorry! The correct answer is c");
System.out.println();
 
//Question #5
System.out.println("5. 2 + 3 + 5 = ?   a.7  b.8  c.9  d.10");
System.out.print("Enter your answer: ");
a2 = System.in.read();System.in.read();System.in.read();
 
if (a5 == 'd')
 
System.out.println("Correct!");
System.out.println();
else
System.out.println("Sorry! The correct answer is d");
System.out.println();
 

 

 
}
}
  

I haven't started on the percentage calculation, or know how I should go about it regarding how many answers are right.

[Michael Dunn]

might be easier for you if you were to create a Question object.
possible fields - the question itself, an array of choices, the correct answer etc
possible methods - displayQuestion(), displayChoices() etc

you can now put these Questions into a Question[]

iterate the Question[]:
display the question
display the choices
read the answer
compare to Question object's correct answer (if correct, correctCounter++)

do your percentages

[Jeremy Parsons]

I don't think I can do the Question object thing because I haven't learned it yet and I think they want me to use only what I have learned so far..

Is that like a switch statement?

[Henry Wong]

  if (a1 == 'c')
    System.out.println("Correct!");
    System.out.println();
  else
    System.out.println("Sorry! The correct answer is c");
    System.out.println();

In Java, the "if" and "else" statements only execute one line (that follows it). If you want to run more than one line, you need to put it in blocks -- or you'll get "else without if" compilation errors.

Basically like this...

  if (a1 == 'c') {
    System.out.println("Correct!");
    System.out.println();
  } else {
    System.out.println("Sorry! The correct answer is c");
    System.out.println();
  }

Henry

[Michael Dunn]

> Is that like a switch statement?

No, it's a class

class Question
{
  fields
  constructor
  methods
}

then you create the objects
Question q1 = new Question(...);

[Jeremy Parsons]

ok, now I'm getting variable a3,a4, and a5 might not have been initialized..
I thought I did initialize them correctly because the first two work ok..

 
public class MathTest
{
 
public static void main(String[]args) throws Exception
{
 
int a1,a2,a3,a4,a5;
 
 
// Question #1
System.out.println("1. 7 + 2 = ?  a.6  b.8  c.9  d.10");
System.out.print("Enter your answer: ");
a1 = System.in.read();System.in.read();System.in.read();
 
if (a1 == 'c')
{
System.out.println("Correct!");
System.out.println();
}
else
{
System.out.println("Sorry! The correct answer is c");
System.out.println();
}
//Question #2
System.out.println("2. 9 - 5 = ?  a.2  b.4  c.6  d.8");
System.out.print("Enter your answer: ");
a2 = System.in.read();System.in.read();System.in.read();
 
if (a2 == 'b')
{
System.out.println("Correct!");
System.out.println();
}
else
{
System.out.println("Sorry! The correct answer is b");
System.out.println();
}
//Question #3
System.out.println("3. 144/12 = ?  a.10  b.12  c.14  d.16");
System.out.print("Enter your answer: ");
a2 = System.in.read();System.in.read();System.in.read();
 
if (a3 == 'b')
{
 System.out.println("Correct!");
System.out.println();
}
else
{
System.out.println("Sorry! The correct answer is b");
System.out.println();
}
//Question #4
System.out.println("4. 5 * 5 = ?  a.10  b.20  c.25  d.125");
System.out.print("Enter your answer: ");
a2 = System.in.read();System.in.read();System.in.read();
 
if (a4 == 'c')
{
System.out.println("Correct!");
System.out.println();
}
else
{
System.out.println("Sorry! The correct answer is c");
System.out.println();
}
//Question #5
System.out.println("5. 2 + 3 + 5 = ?   a.7  b.8  c.9  d.10");
System.out.print("Enter your answer: ");
a2 = System.in.read();System.in.read();System.in.read();
 
if (a5 == 'd')
{
System.out.println("Correct!");
System.out.println();
}
else
{
System.out.println("Sorry! The correct answer is d");
System.out.println();
}
 
 
 
 
}
}

[ September 03, 2006: Message edited by: Jeremy Parsons ]

[Jeroen T Wenting]

Originally posted by Jeremy Parsons:
I don't think I can do the Question object thing because I haven't learned it yet and I think they want me to use only what I have learned so far..

That would be the day, a teacher who's unhappy with his students learning on their own...
Of course most teachers these days (and rightly so given the attitude of most students these days) don't expect their pupils to put in any effort beyond the bare minimum to get a passing grade (and preferably turn in work done by others instead), but that doesn't mean they wouldn't like things to be different.

[parshuram bingi]

Jeremy Parsons,

The following is the code and tested and it works fine, here you need to understand that after reading the input(you should not support to read 3 times as you done in your program) you should clean the buffer for that I am using 2 dummy read statements(any one is there any better way?).

import java.io.IOException;

public class MathTest
{

public static void main(String[]args) throws Exception
{

int a1,a2,a3,a4,a5;
int userInput;


// Question #1
System.out.println("1. 7 + 2 = ? a.6 b.8 c.9 d.10");
System.out.print("Enter your answer: ");
a1 = System.in.read();
userInput=System.in.read();
userInput=System.in.read();

if (a1 == 'c')
{

System.out.println("Correct!");
System.out.println();
}
else
{
System.out.println("Sorry! The correct answer is c");
System.out.println();
}

//Question #2
System.out.println("2. 9 - 5 = ? a.2 b.4 c.6 d.8");
System.out.print("Enter your answer: ");
a2 = System.in.read();
userInput=System.in.read();
userInput=System.in.read();

if (a2 == 'b')
{
System.out.println("Correct!");
System.out.println();
}
else
{System.out.println("Sorry! The correct answer is b");
System.out.println();
}
//Question #3
System.out.println("3. 144/12 = ? a.10 b.12 c.14 d.16");
System.out.print("Enter your answer: ");
a3 = System.in.read();
userInput=System.in.read();
userInput=System.in.read();

if (a3 == 'b')
{
System.out.println("Correct!");
System.out.println();
}
else
{System.out.println("Sorry! The correct answer is b");
System.out.println();
}
//Question #4
System.out.println("4. 5 * 5 = ? a.10 b.20 c.25 d.125");
System.out.print("Enter your answer: ");
a4 = System.in.read();
userInput=System.in.read();
userInput=System.in.read();

if (a4 == 'c')
{
System.out.println("Correct!");
System.out.println();
}
else
{System.out.println("Sorry! The correct answer is c");
System.out.println();
}
//Question #5
System.out.println("5. 2 + 3 + 5 = ? a.7 b.8 c.9 d.10");
System.out.print("Enter your answer: ");
a5 = System.in.read();
userInput=System.in.read();
userInput=System.in.read();

if (a5 == 'd')
{
System.out.println("Correct!");
System.out.println();
}
else
{System.out.println("Sorry! The correct answer is d");
System.out.println();
}




}
}

-Ram.

[Jeremy Parsons]

ok, first of all I am not in a "class", I am self teaching through a distance learning school..

Second, I'm not asking someone to do my program for me and I turn it in, etc.. I am seeking help, but you are not helping, instead acting like an ass...

I'm working to figure out what my problem with my code is, and that's what this website is all about is Java, learning, and helpful people..

If you don't like it, stay off my posts...

[Henry Wong]

ok, now I'm getting variable a3,a4, and a5 might not have been initialized..
I thought I did initialize them correctly because the first two work ok..

Take a look at your code for question 3, 4, and 5. I believe that you may have gotten a bit aggressive with the cut-n-paste. Did you actually set the a3, a4, and a5 variables?

Henry

[Jeremy Parsons]

I know why I got the last error.. in the line of code

a2 = System.in.read();System.in.read();System.in.read();

After the second one, I accidentally made them all a2 variables beside the input.. I changed and it now compiles..

[Jeremy Parsons]

lol thanks.. I believe we both noticed it at the same time..

Now I just need help figuring out how to calculate correct answers for a total percentage of correct to display..

should I do something like this..

if (a1 && a2 && a3 && a4 && a5)
System.out.println("You graded 100%");

and just repeat that but take one away from each??

[parshuram bingi]

It is not fisable to do so...., how can you do the same if you are having more no of question. I suggest to go with the counter. when ever you find a correct answer increment the counter and finally you can computer the percentage with the counter.

-ram

[Jeremy Parsons]

ah, didn't think about a counter, I was thinking way too complex or something.. Thanks, I'll try a counter and post the results..

[Jeremy Parsons]

I have completed the code, and the counter works, but when my calculation into a percentage displays say if I get all 5 right, it only displays 20%

Here's the full code..

public class MathTest
{
 
public static void main(String[]args) throws Exception
{
 
int a1,a2,a3,a4,a5;
int counter = 0;
int percent;
 

// Question #1
System.out.println("1. 7 + 2 = ?  a.6  b.8  c.9  d.10");
System.out.print("Enter your answer: ");
a1 = System.in.read();System.in.read();System.in.read();
 
if (a1 == 'c')
{
++counter;
System.out.println("Correct!");
System.out.println();
}
else
{
System.out.println("Sorry! The correct answer is c");
System.out.println();
}
//Question #2
System.out.println("2. 9 - 5 = ?  a.2  b.4  c.6  d.8");
System.out.print("Enter your answer: ");
a2 = System.in.read();System.in.read();System.in.read();
 
if (a2 == 'b')
{
++counter;
System.out.println("Correct!");
System.out.println();
}
else
{
System.out.println("Sorry! The correct answer is b");
System.out.println();
}
//Question #3
System.out.println("3. 144/12 = ?  a.10  b.12  c.14  d.16");
System.out.print("Enter your answer: ");
a3 = System.in.read();System.in.read();System.in.read();
 
if (a3 == 'b')
{
++counter;
 System.out.println("Correct!");
System.out.println();
}
else
{
System.out.println("Sorry! The correct answer is b");
System.out.println();
}
//Question #4
System.out.println("4. 5 * 5 = ?  a.10  b.20  c.25  d.125");
System.out.print("Enter your answer: ");
a4 = System.in.read();System.in.read();System.in.read();
 
if (a4 == 'c')
{
++counter;
System.out.println("Correct!");
System.out.println();
}
else
{
System.out.println("Sorry! The correct answer is c");
System.out.println();
}
//Question #5
System.out.println("5. 2 + 3 + 5 = ?   a.7  b.8  c.9  d.10");
System.out.print("Enter your answer: ");
a5 = System.in.read();System.in.read();System.in.read();
 
if (a5 == 'd')
{
++counter;
System.out.println("Correct!");
System.out.println();
}
else
{
System.out.println("Sorry! The correct answer is d");
System.out.println();
}
 
percent = counter * 20 / 5 ; //calculates questions right into percent
 
System.out.println("Congratulations, you have passed with a score of " + percent + "%");
 

}
}
 
    

What do I need to look at to fix the calculation? PS I'm not that great at math as it is...lol

[Jeremy Parsons]

ok I got it, you can disregard the last post.. I should have taken down the division part..