Verify my work

[xcrypted1]

Evening all,

My assignment is as follows:

Consider a program that administers multiple-choice quizzes. The student needs to provide a response such as A or D. Your job will be to check for input errors in the student response string. Check that the string has length 1, and that it is a letter between A and the last valid choice for the problem.

Complete the following code:

public class Inputs
{
   /**
      Gets the choice that the user provided, or null if the 
      user didn't provide a valid choice.
      @param input the user input
      @param maxChoice the maximum valid choice, e.g. "D" if there
      are four choices.
      @return the user input if it was a valid choice (i.e. length 1
      and between "A" and maxChoice), null otherwise
   */
   public String getChoice(String input, String maxChoice)
   {
      // Your work here


   }
}

The validation website it currently down, so here is what I did. Would some of you experts take a look and see if I did this correctly, please.

Thank you!

public class Inputs
{
   /**
      Gets the choice that the user provided, or null if the 
      user didn't provide a valid choice.
      @param input the user input
      @param maxChoice the maximum valid choice, e.g. "D" if there
      are four choices.
      @return the user input if it was a valid choice (i.e. length 1
      and between "A" and maxChoice), null otherwise
   */
   public String getChoice(String input, String maxChoice)
   {
      String aInput;
      String amaxChoice;
    
      aInput = input;
      amaxChoice = maxChoice;
      
      int choiceA = 1;
      int choiceB = 2;
      int choiceC = 3;
      int choiceD = 4;
      
      
   
      
      if (aInput.length() == 1)
          {
              if (aInput.equals("A"))
                  {
                      System.out.println("Valid answer: A");
                  }
              else if (aInput.equals("B"))
                  {
                      System.out.println("Valid answer: B");
                  }
              else if (aInput.equals("C"))
              
                  {
                      System.out.println("Valid answer: C");
                  }
              else if (aInput.equals("D"))
                  {
                      System.out.println("Valid answer: D");
                  }
              else
                  {
                      System.out.println("Invalid answer");
                  }
           }
       else
        {
            System.out.println("Please enter only one letter");
        }
        
           
        
                    
            
            return aInput;
              
      


   }
}

[zeroliken]

Is it required to use maxChoice or is it not really necessary cause you did not refer to it for the process?
plus you did not use these variables too

int choiceA = 1;
int choiceB = 2;
int choiceC = 3;
int choiceD = 4;

[dantinkakkar]

As @zeroliken said, there was no need for the choiceA, choiceB, choiceC, and choiceD variables. Other than what he said, I don't see anything wrong with your code. You should run it once and check it out! :)

[stultuske]

there is one remark though:
you only should return the user input if it was valid, null otherwise, so:

if (aInput.length() == 1)
          {
              if (aInput.equals("A"))
                  {
                      System.out.println("Valid answer: A");
                  }
          //    ... your other if's
              else
                  {
                      System.out.println("Invalid answer");
                      return null; // since here it would be invalid
                  }
           }
       else
        {
            System.out.println("Please enter only one letter");
            return null; // here also, it would be invalid
        }
            // with invalid input, you won't reach this statement, so you would not
            // return the input if it was invalid
 
            return aInput;

[xcrypted1]

Thank you all for the input.

there is one remark though:
you only should return the user input if it was valid, null

Im sure I need to utilize the getMaxChoice but I'm not sure how. Our book is vague and severely lacks examples "Big Java"

[stultuske]

all books seem vague, but sometimes that's just because the example is not very extensive.
I never said you're not supposed to use getMaxChoice, I'm just pointing out that in your assignment, it says:

@return the user input if it was a valid choice (i.e. length 1
and between "A" and maxChoice), null otherwise

the return annotation tells you what your method is supposed to return and in which case. so, is the choice invalid, return null; else, return the String you used as input. that's what I did in the bit code I adapted.