如何按字母顺序排序而忽略区分大小写？

collections android java

2022-08-31 15:03:14

我有这个代码，但仅适用于小写字母。我希望这在忽略大写字母的同时对列表进行排序。

package sortarray.com;

import java.util.ArrayList;
import java.util.List;

import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.widget.TextView;

public class SortArray extends Activity {
    ArrayList<String[]> matchedFruits = new ArrayList<String[]>();
    TextView selection;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        String fruits[] = new String[7];// Sorted array
        fruits[0] = "apple";
        fruits[1] = "apricot";
        fruits[2] = "banana";
        fruits[3] = "mango";
        fruits[4] = "melon";
        fruits[5] = "pineapple";
        fruits[6] = "peach";
        char currChar = fruits[0].charAt(0);// Get first char of first element

        boolean match = false;
        int len = fruits.length;
        List<String> tmp = new ArrayList<String>();

        for (int i = 1; i < len; i++) {
            Log.d("Comparing ", fruits[i].charAt(0) + "," + currChar);
            if (fruits[i].charAt(0) == currChar) {
                if (match == false)// new match?
                {
                    match = true;// Reset search
                    tmp.clear();// clear existing items
                    tmp.add(fruits[i - 1]);
                    Log.d("Started new list ", fruits[i - 1]);
                } else {
                    tmp.add(fruits[i - 1]);
                    Log.d("Added to list ", fruits[i - 1]);
                }
            } else {
                match = false;
                tmp.add(fruits[i - 1]);
                matchedFruits.add(tmp.toArray(new String[tmp.size()]));// add to
                                                                        // final
                                                                        // list
                Log.d("Finished a list ", fruits[i - 1]);
                tmp.clear();// clear existing items

            }
            currChar = fruits[i].charAt(0);

        }
        tmp.add(fruits[len - 1]);
        matchedFruits.add(tmp.toArray(new String[tmp.size()]));// add left over
                                                                // items
        printList();
    }

    void printList()
    {
    //Print the list 
        TextView selection = (TextView) findViewById(R.id.tv);
        String mssg="";
    for(int i=0;i<matchedFruits.size();i++)
    {
            String tmp2[]= matchedFruits.get(i);

            for (int j = 0; j < tmp2.length; j++) {
                //Log.d("Final list", "Array #" + i + "[" + j + "]," + tmp2[j]);
                mssg += tmp2[j].toString();

            }
            //selection.setText("\n");
            selection.setText(mssg);

    }
    }
}

答案 1

Collections.sort(listToSort, String.CASE_INSENSITIVE_ORDER);

答案 2

目前还不清楚您要做什么，但您可以像这样对列表进行排序：

List<String> fruits = new ArrayList<String>(7);

fruits.add("Pineapple");
fruits.add("apple");
fruits.add("apricot");
fruits.add("Banana");
fruits.add("mango");
fruits.add("melon");        
fruits.add("peach");

System.out.println("Unsorted: " + fruits);

Collections.sort(fruits, new Comparator<String>() {
    @Override
    public int compare(String o1, String o2) {              
        return o1.compareToIgnoreCase(o2);
    }
});

System.out.println("Sorted: " + fruits);