学习s.toCharArray()和new String(chars)

参考代码:

import java.util.Scanner;
public class Main
{
    public static void main(String args[])
    {
        Scanner ss=new Scanner(System.in);
        String s=ss.nextLine();
        if((int)s.length()==8)
        {
            char chars[]=s.toCharArray();
            chars[4]=':';
            chars[6]=':';
            System.out.print(new String(chars));
        }
        else if((int)s.length()==9)
        {
            if(s.charAt(6)!='-')
            {
                char chars[]=s.toCharArray();
                chars[4]=':';
                chars[7]=':';
                System.out.print(new String(chars));
            }
            else
            {
                char chars[]=s.toCharArray();
                chars[4]=':';
                chars[6]=':';
                System.out.print(new String(chars));
            }
        }
        else if((int)s.length()==10)
        {
            char chars[]=s.toCharArray();
            chars[4]=':';
            chars[7]=':';
            System.out.print(new String(chars));
        }
    }
}