Modifying Given Code

[jmscarlet9]

One of my assignments this week is to modify a given program that sorts an array of integers from lowest to highest so that it will sort names from last in the alphabet to first (for example: Input: Crowe, Clooney, Pitt, Gibson; Returns: Pitt, Gibson, Crowe, Clooney)

I thought I was doing okay, but there are 2 places in the code that are looking for int variables. The teacher said the code changes would be minimal so I'm at a lost as to what to do next.

Here's my updated code:

public class SelectionSortTester_JC {
       public static void main(String[] args) {
      //declare vars
         String[] data = {"Crowe", "Clooney", "Pitt", "Gibson"};
      
       //print array (unsorted)
         System.out.println("Unsorted: ");
         printArray(data);
      
      //call sort method
         selectionSort(data);
      
      //print array (sorted)
         System.out.println("Sorted: ");
         printArray(data);      
      } // eo main
   
   
    //METHODS-> 
    //---------
    
   	//prints out array of int all on 1 line.
   	//parameter passed: address of int array
		//no return statement needed since change is made to actual array
		public static void printArray(String[] inData) {
         for(int i = 0; i < inData.length; i++){
            System.out.print(inData[i] + "  ");}
         System.out.println();
      
      }
   	
   	//swaps two values in an array of int
   	//parameters passed: address of int array, indices of two elements to swap
		//no return statement needed since change is made to actual array
      public static void swap(String[] inData, int current, int min) {
         int temp = inData[current];
         inData[current] = inData[min];
         inData[min] = temp;
      }//eo swap
   
      //Finds index of smallest entry in array
		//parameters passed: address of int array, index of first element to be processed
      //returns index of smallest element in array  
		public static int findSmallest(String[] inData, int start) {
         int smallestIdx = start;
         for (int i = (start + 1); i < inData.length; i++) {
            if(inData[i] < inData[smallestIdx]) {
               smallestIdx = i;
            }//eo if
         }//eo for
         return smallestIdx;
      }//eo findSmmalest
   	
   	
   	//selection sort method
   	//parameter passed: address of int array
		//no return statement needed since change is made to actual array
       public static void selectionSort(String[] inData) {
         int indexOfCurrentSmallest;
         for(int i = 0; i<(inData.length - 1); i++) {
            indexOfCurrentSmallest = findSmallest(inData,i);  //finds smallest
            swap(inData,i,indexOfCurrentSmallest); //swaps smallest with current
         }//eo for			     
      }//eo selectionSort method
   } // eo class

I changed:

Line 4 to take in strings.

Line 25 to use a String array.

Line 35 to use a String array.

Line 44 to use a String array.

Line 58 to use a String array.

The incompatible type errors are showing up on lines 36 and 38 (temp, current and min are set to integers but I don't know how to make them work for strings).

I'm also getting a bad operand type on line 47 since you can't do a < on Strings, but again, I don't know how to change it.

Not too mention, the changes should be "minimal"....

HELP!

[DarrylBurke]

The incompatible type errors are showing up on lines 36 and 38 (temp, current and min are set to integers but I don't know how to make them work for strings).

You do. You've done it already.

A variable declaration and initialization follows the form

Type variableName = variableValue;

where the variable value has a type that is assignment compatible with the declared type. In your present line 36, you have

int temp = inData[current];

But. inData is an array of String -- each element, like inData[0], inData[1] ... inData[current] is a String. So, what should be the Type of the variable temp?

db

[jmscarlet9]

Ok, that was me being stupid after 8 hours of trying to figure stuff out. And it may still be continuing, how do I fix the < error (error: bad operand types for binary operator '<') from line 7 below? I know that inData are Strings, but aren't i and smallestIdx integers? How can I get this to work?

      //Finds index of smallest entry in array
		//parameters passed: address of int array, index of first element to be processed
      //returns index of smallest element in array  
		public static int findSmallest(String[] inData, int start) {
         int smallestIdx = start;
         for (int i = (start + 1); i < inData.length; i++) {
            if(inData[i] < inData[smallestIdx]) {
               smallestIdx = i;
            }//eo if
         }//eo for

[Fubarable]

Questions to ask yourself:

• What is inData an array of?
• Does the < operator make sense for this data type?

[jmscarlet9]

It doesn't make sense because this is comparing #s, but I want it to compare the letters and then print it in reverse alphabet. So, I need it to compare letters. I not sure how to switch it from one to the other.

[JosAH]

It doesn't make sense because this is comparing #s, but I want it to compare the letters and then print it in reverse alphabet. So, I need it to compare letters. I not sure how to switch it from one to the other.

If all else fails read the API documentation; it's all in there.

kind regards,

Jos