Creating a string array from random user input

Question

I want to have a user input a random string of letters, put those in an array, then sort them alphabetically. Problem I have is putting the input into an array. What I have is:

import java.util.Scanner;
public class ArraySort {
public static void main(String[] args)
{
    System.out.println("Enter letters");
    Scanner kb = new Scanner(System.in);
    String input = kb.nextLine();
    int stringLength = input.length();
    String[] stringArray = new String[stringLength];

    for (int i = 0; i < stringLength; i++)
    {
        stringArray[i] = input;     
    }

    System.out.println(stringArray);

}

}

This gives me [Ljava.lang.String;@55f96302 when I print.

To convert the input string to an array of characters use `input.toCharArray()` — Roger Gustavsson, May 09 '15 at 22:15

score 3 · Answer 1 · answered May 09 '15 at 22:14

3

You have two problems, you're not printing the Array correctly, and you're storing the entire input in each cell of the array. Try:

    for (int i = 0; i < stringLength; i++)
    {
        stringArray[i] = input.charAt(i)+"";  
        System.out.println(stringArray[i]);   
    }

answered May 09 '15 at 22:14

Ryan

2,058
1
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Forgot about the need to iterate. Thanks. – AndoTwo May 09 '15 at 22:34

Thomas Junk · Answer 2 · 2015-05-09T22:34:54.350

You are making 2 major mistakes:

1) You are assigning each string the whole input stringArray[i] = input;

2) You have to iterate over each element of your string array. In Java8 this could be done easily with Arrays.stream().

A corrected Version of your code is:

import java.lang.reflect.Array;
import java.util.Arrays;
import java.util.Scanner;
public class Main {
    public static void main(String[] args)
    {
        System.out.println("Enter letters");
        Scanner kb = new Scanner(System.in);
        String input = kb.nextLine();
        int stringLength = input.length();
        String[] stringArray = new String[stringLength];

        for (int i = 0; i < stringLength; i++)
        {
            stringArray[i] = Character.toString(input.charAt(i));
        }

        Arrays.stream(stringArray).forEach(System.out::print);

    }
}

Btw. String[] stringArray=input.split(""); would be much shorter.

Additional: If you want sorted output:

stringArray=Arrays.stream(stringArray).sorted().toArray(String[]::new);
Arrays.stream(stringArray).forEach(System.out::print);

And you are done.

import java.lang.reflect.Array;
import java.util.Arrays;
import java.util.Scanner;
public class Main {
    public static void main(String[] args)
    {
        System.out.println("Enter letters");
        Scanner kb = new Scanner(System.in);
        String input = kb.nextLine();
        String[] stringArray=input.split("");
        stringArray=Arrays.stream(stringArray).sorted().toArray(String[]::new);

        Arrays.stream(stringArray).forEach(System.out::print);

    }
}

That's amazing. How the lack of a for loop doesn't break that code I'm not quite sure yet. Also never seen that input.split(" ") thing, and the double colons. — AndoTwo, May 09 '15 at 22:44

copeg · Answer 3 · 2015-05-09T22:19:04.770

0

To get the String form of an array, use the Arrays class toString method.

System.out.println(Arrays.toString(stringArray));

Also note the sort method of this class, although in the code's current state each item of your array will be equal to the input line.

edited May 09 '15 at 22:19

answered May 09 '15 at 22:13

copeg

8,290
19
28

What is the difference between treating each individual letter in the array as a char and getting the String form? – AndoTwo May 09 '15 at 22:35

Creating a string array from random user input

3 Answers3