How do I sort an array ignoring capitalization?

Question

I use sort() to sort my array alphabetically, but it does so from A-Z to a-z. I try to capitalize each word beforehand, but it doesn't work unless it's being printed out, which should be happening after the sorting. At the moment, with this code, it will list the pupils with capital letters, but if it was inputted as lowercase, it will be sorted as lowercase. Putting the capitalize() in the initial for loop, right after assigning the input to the array, doesn't work. Any solutions?

import java.util.Scanner;
import java.util.Arrays;

public class Pupils {
public static void main(String[] args) {

    Scanner scan = new Scanner(System.in);
    boolean loop = true;
    int names = 0;

    String[] ay = new String[1000];

    for(int i = 0; loop == true; i++) {
            System.out.println("Enter name: ");
            ay[i] = scan.nextLine();
            names++;
            if (ay[i].equals("0")) {
                loop = false;
                ay[i] = " ";
        }
    }

    String[] aay = new String[names - 1];

    for(int i = 0; i < aay.length; i++) {
        aay[i] = ay[i];
    }

    if (names == 1) {
        System.out.print("There are no people in our class.");
    } else if (names == 2) {
        System.out.print("The person in our class is ");
    } else {
        System.out.print("The people in our class are ");
}
    Arrays.sort(aay);
    for(int i = 0; i < names - 1; i++) {
        if(i == names - 2) {
            System.out.print(capitalize(aay[i]) + ".");
        } else if (i == names - 3) {
            System.out.print(capitalize(aay[i]) + " and ");
        } else {
            System.out.print(capitalize(aay[i]) + ", ");
        }
    }

}
public static String capitalize(String line)
{
  return Character.toUpperCase(line.charAt(0)) + line.substring(1);
}

}

pls search for SO before asking. look here http://stackoverflow.com/questions/11176227/simple-way-to-sort-strings-in-the-alphabetical-order — Michael, Feb 02 '15 at 19:53

score 6 · Accepted Answer · answered Feb 02 '15 at 19:50

6

What about using Arrays.sort() with a Comparator? Note that there is a suitable comparator defined in String, so:

Arrays.sort(aay, String.CASE_INSENSITIVE_ORDER);

should do the job.

answered Feb 02 '15 at 19:50

1

There's even one already made: `String.CASE_INSENSITIVE_ORDER` – Nicholas Daley-Okoye Feb 02 '15 at 19:53
This will only work for ASCII characters. For instance, the string "pirate" would be sorted before "piñata". The correct way to sort alphabetically is with a [Collator](https://docs.oracle.com/javase/8/docs/api/java/text/Collator.html), usually obtained with [Collator.getInstance()](https://docs.oracle.com/javase/8/docs/api/java/text/Collator.html#getInstance--). – VGR Feb 02 '15 at 20:33

score 0 · Answer 2 · answered Feb 02 '15 at 20:06

I suggest storing all the data in the array in lowercase. It will simplify sorting as well as search (if you search for a student in the array, and it was entered as, say "Walter" and you are looking for "walter", you won't find it. If you use lowercase both for storage and for search, it will work).

And since you capitalize the names for printing anyway, the names will still be displayed capitalized.

So instead of doing

        ay[i] = scan.nextLine();

You can do:

        ay[i] = scan.nextLine().toLowerCase();

How do I sort an array ignoring capitalization?

2 Answers2