Java Alphabetizing Strings

Question

I have a project for class were I need to get 4 different strings inputted and then output them in alphabetical order.

So far I have this:

String wd1         


        

Answer 1

Typical divide and concur strategy could be applied. Think about merge sort, sort first 2 and last 2 strings, after that merge results.

if(s2<s1) swap(s1,s2)
if(s4<s3) swap(s3,s4)

if(s1<s3) {
  print(s1)
  if(s2<s3){
    print(s2)
    print(s3)
    print(s4)
  } else {
    print(s3)
    if(s2<s4){
      print(s2)
      print(s4)
    } else {
      print(s4)
      print(s2)
    }
  }
} else {
  print(s3)
  if(s4<s1){
    print(s4)
    print(s1)
    print(s2)
  } else {
    print(s1)
    if(s4<s2){
      print(s4)
      print(s2)
    } else {
      print(s2)
      print(s4)
    }
  }
}

Answer 2

How about putting the Strings in a List and call the sort() method?

The Java String class implements the 'Comparable' interface and thus already has the compareTo() method, which should compare the strings in order.

Answer 3

boolean swapped = false;
do {
  swapped = false;
  if (w2.compareTo(w1) < 0) {
    String tmp = w2;
    w2 = w1;
    w1 = tmp;
    swapped = true;
  }
  if (w3.compareTo(w2) < 0) {
    String tmp = w3;
    w3 = w2;
    w2 = tmp;
    swapped = true;
  }
  if (w4.compareTo(w3) < 0) {
    String tmp = w4;
    w4 = w3;
    w3 = tmp;
    swapped = true;
  }
} while (swapped)

System.out.println(w1);
System.out.println(w2);
System.out.println(w3);
System.out.println(w4);

Answer 4

For comparing more than 2 strings you should put the strings in an array and then run them through a sorting method

public class SortLetters2 {
public String[] sort(String[] asd) {
    String[] sorted = asd.clone();
    for (int i = 0; i < sorted.length; i++) {
        for (int j = i + 1; j < sorted.length; j++) {
            int compare = sorted[i].compareTo(sorted[j]);
            if ((compare > 0) && (i != j)) {
                //compare two strings
                String temp = sorted[j];
                sorted[j] = sorted[i];
                sorted[i] = temp;
            }
        }
    }
    return sorted;
}
public static void main(String[] args) {
    SortLetters2 list1 = new SortLetters2();
    //SortLetters2 is the class name
    Scanner scan1 = new Scanner(System.in);
    String wd1, wd2, wd3, wd4;
    System.out.println("Type Word One: ");
    wd1 = scan1.next();
    System.out.println("Type Word Two: ");
    wd2 = scan1.next();
    System.out.println("Type Word Three: ");
    wd3 = scan1.next();
    System.out.println("Type Word Four: ");
    wd4 = scan1.next();
    String array[] = {wd1, wd2, wd3, wd4};
    //set array equal to the inputs
    String[] sortedArray = list1.sort(array);
    for (int i = 0; i < sortedArray.length; i++) {
        if (i == sortedArray.length - 1) {
            System.out.println(sortedArray[i]);
        } else {
            System.out.print(sortedArray[i] + ",");
        }
    }
    //run sorting program
}
}

Answer 5

You need to compare first string with the rest three to find which is alphabetically first. after that you need to compare among the rest 3 and so on.

Answer 6

The easiest way to do what you are looking for is to put them in a list, then use list.sort() to put them in order.