姓名排序

///yuec2 yue cheng
package lab1;

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

/**NameSorter class takes n number of names in the form of string inputs 
 * from the user. It then asks user for which name to search for. 
 * It sorts the names entered by the user, and then prints the 
 * position of the search-name in the sorted list of the names, 
 * if it is found.
 */

public class NameSorter {
    Scanner input = new Scanner(System.in);
    
    /**getNameInputs takes an int parameter n and creates an array of size n. 
     * It then asks user to Enter n names that get stored in the array. 
     * It uses the helper method toTitleCase() to convert all names to Title case. 
     * It returns the array filled with names entered by the user.
     */
    String[] getNameInputs(int n) {
        //write your code here
        String[] names = new String[n];
        for (int i = 0; i < n; i++) {
            names[i] = input.next();
        }
        return names;
    }
    
    /**toTitleCase() takes one string argument as name and returns the string in title case. 
     * If the name is null or the string is empty, it returns null.
     */
    String toTitleCase(String name) {
        //write your code here
        if (name == null || name.length() == 0) 
            return null;
        char c = name.charAt(0);
        char cap = Character.toUpperCase(c);
        String sub = name.substring(1);
        StringBuilder sb = new StringBuilder();
        sb.append(cap);
        for (int i = 0; i < sub.length(); i++) {
            sb.append(Character.toLowerCase(sub.charAt(i)));
        }
        return sb.toString();
    }

    /**sortAndSearch() takes two arguments. The first is an array of strings and the second
     * is a searchString. The method first sorts the array in increasing alphabetical order, 
     * and prints it in that order.
     * It then searches for the searchString in a case-insensitive way. If the searchString is found,
     * it returns the position of the searchString according to the sorted list. 
     * If it is not found, then it returns -1.
     */
    int sortAndsearch(String[] strings, String searchString) {
        int pos = -1;
        if (strings == null || strings.length == 0 || searchString == null) 
            return pos;
        //write your code here
        Arrays.sort(strings);
        for (int i = 0; i < strings.length; i++) {
            if (strings[i].equalsIgnoreCase(searchString)) 
                return i;
        }
        return pos;
    }

    /**DO NOT CHANGE THIS METHOD */
    public static void main(String[] args) {
        NameSorter ns = new NameSorter();
        System.out.println("*** How many names to store? ***");
        int n = ns.input.nextInt();
        if (n > 0) {
            String[] names = ns.getNameInputs(n);
            System.out.println("*** Enter the name to search ***");
            String name = ns.input.next();
            int position = ns.sortAndsearch(names, name);
            if (position >=0 ) System.out.println(name + " found at position " + (position+1));
            else System.out.println("Sorry! " + name + " not found!");
        } else System.out.println("Good Bye!");
    }
}

读懂题、先写cc  equalsIgnoreCase等给的函数要用

Arrays.sort(strings);自动按首字母排序

 

 

注意names[i] = input.next();和nextline()的区别

String[] getNameInputs(int n) {
        //write your code here
        String[] names = new String[n];
        for (int i = 0; i < n; i++) {
            names[i] = input.next();
        }
        return names;
    }