阅读三个单词并按字典顺序对其进行排序

Question

I am trying to create a program that asks the User to type three words and sort them in lexicographic order.

EXAMPLE;

• Enter three words separated by spaces:
• Pear Orange Apple
• Apple
• Orange
• Pear

The program is working fine (if I attempt the above example) except for one type of combination example that I will show below.

EXAMPLE;

• Enter three words separated by spaces:
• Orange Apple Pear
• Apple
• Pear
• Pear

The program is skipping the first word (Orange) if it is supposed to appear in the middle of the three words.

I believe that this line of code is affecting the program because it says that "this assigned value is never used" but I'm not sure how to fix it since I'm still an entry Java learner.

• middle = firstWord;

Because of that line being unused, it's why Pear appeared twice.

import java.util.*;
public static void main(String[] args) 
{

Scanner wordInput = new Scanner(System.in);
String firstWord;
String secondWord;
String thirdWord;


System.out.println("Enter three words separated by spaces: ");

firstWord = wordInput.next();
secondWord = wordInput.next();
thirdWord = wordInput.next();


String top = firstWord;
String bottom = firstWord;
if( top.compareTo(secondWord) > 0) 
{ 
top = secondWord; 
} 
if( top.compareTo(thirdWord) > 0) 
{ 
top = thirdWord; 
} 
if( bottom.compareTo(secondWord) < 0) 
{ 
bottom = secondWord; 
} 
if( bottom.compareTo(thirdWord) < 0) 
{ 
bottom = thirdWord; 
}   
String middle;
if( !firstWord.equals(bottom) && !firstWord.equals(top) ) 
{ 
middle = firstWord; 
} 
if( !secondWord.equals(bottom) && !secondWord.equals(top) ) 
{ 
middle = secondWord; 
} 
else 
{ 
middle = thirdWord; 
} 

System.out.println( top ); 
System.out.println( middle ); 
System.out.println( bottom ); 


}
}

Does anyone what I am missing or doing wrong? :( Please and thank you for any help!

Answer 1

Rather than adding so much conditions you can simply do this by TreeSet :

public static void main(String[] args) throws FileNotFoundException, IOException{
        Scanner wordInput = new Scanner(System.in);
        String firstWord;
        String secondWord;
        String thirdWord;


        System.out.println("Enter three words separated by spaces: ");

        firstWord = wordInput.next();
        secondWord = wordInput.next();
        thirdWord = wordInput.next();

        TreeSet<String> treeSet=new TreeSet<>();

        treeSet.add(firstWord);
        treeSet.add(secondWord);
        treeSet.add(thirdWord);
        for(String s:treeSet){
            System.out.println(s);
        }
    }

And if you have duplicate:

    Map<String, Integer> treeMap=new TreeMap<>();
    if(treeMap.containsKey(firstWord)){
        Integer i=treeMap.get(firstWord);
        i++;
        treeMap.put(firstWord, i);
    }
    else{
        treeMap.put(firstWord, 1);
    }
    if(treeMap.containsKey(secondWord)){
        Integer i=treeMap.get(secondWord);
        i++;
        treeMap.put(secondWord, i);
    }
     else{
        treeMap.put(secondWord, 1);
    }
    if(treeMap.containsKey(thirdWord)){
        Integer i=treeMap.get(thirdWord);
        i++;
        treeMap.put(thirdWord, i);
    }
     else{
        treeMap.put(thirdWord, 1);
    }
    for(String s:treeMap.keySet()){
        int k=treeMap.get(s);
        while(k>0){
            System.out.println(s);
            k--;
        }
    }

Answer 2

You are missing an else in selecting the middle word: the first if correctly assigns Orange to it, but then the last if / else re-assigns Pear to it.

Here is how to fix your code:

if( !firstWord.equals(bottom) && !firstWord.equals(top) ) {
    middle = firstWord; 
} else if( !secondWord.equals(bottom) && !secondWord.equals(top) ) {
    middle = secondWord; 
}  else  {
    middle = thirdWord; 
} 

Answer 3

Here is another solution with less code

public static void main(String[] args) {
    // TODO code application logic here
    System.out.println("Enter three words separated by spaces: ");
    //Scanner wordsInput = new Scanner(System.in);
    Console console = System.console();

    //List<String> words = new ArrayList<>();
    List<String> words = Arrays.asList(console.readLine().split("\\s+"));
    Collections.sort(words);
    for (String word : words) {
         System.out.println(String.format("- %s",word));
    }
}