how to sort

[Feng]

what is the way to sort alphabetically strings from an array?

(for example lets say we have the strings "Apple", "Key" and "Zebra" in an array of 5 elements.)

[hardwired]

String implements the Comparable interface so we can use the compareTo method for sorting. See first paragraph and "Classes Implementing Comparable" table at Object Ordering for bird's–eye view.

Code:

public class Sorting {
    public static void main(String[] args) {
        String[] array = { "five", "Apple", "Zebra", "Key", "elements" };
        sort(array);
        print(array);
        sortIgnoreCase(array);
        print(array);
    }

    private static void sort(String[] strs) {
        for(int j = 0; j < strs.length; j++) {
            String minValue = strs[j];
            int minIndex = j;
            for(int k = j+1; k < strs.length; k++) {
                if(strs[k].compareTo(minValue) < 1) {
                    minValue = strs[k];
                    minIndex = k;
                }
            }
            if(minIndex != j) {
                // found a lower value - swap elements
                String temp = strs[j];
                strs[j] = minValue;
                strs[minIndex] = temp;
            }
        }
    }
    
    private static void sortIgnoreCase(String[] strs) {
        for(int j = 0; j < strs.length; j++) {
            String minValue = strs[j].toLowerCase();
            int minIndex = j;
            for(int k = j+1; k < strs.length; k++) {
                if(strs[k].toLowerCase().compareTo(minValue) < 1) {
                    minValue = strs[k].toLowerCase();
                    minIndex = k;
                }
            }
            if(minIndex != j) {
                // found a lower value - swap elements
                String temp = strs[j];
                strs[j] = minValue;
                strs[minIndex] = temp;
            }
        }
    }

    private static void print(String[] strs) {
        for(int j = 0; j < strs.length; j++) {
            System.out.print(strs[j]);
            if(j < strs.length-1)
                System.out.print(", ");
        }
        System.out.println();
    }
}