Java，基本数组错误

Question

I am trying to do a Java program that will let me input 10 words, and then the words should be repeated in reverse order (the last first etc).

This is my current code:

import java.util.Scanner;
import java.lang.String;

public class Words {

public static void main(String[] args){

String word[] = {};

for(int x = 0; x < 10; x+=1) {

System.out.println("Input any word");

Scanner input = new Scanner(System.in);
word = new String[] { input.next() };

      }

for(int y = 9; y >= 0; y-=1) {

System.out.println(word[y]);

      }
}}

It gives me the following error when trying to compile:

Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 9 at Words.main(Words.java:21)

I am new to Java and would appreciate help, thanks in advice.

Answer 1

That's not how arrays work. Change String word[] = {}; to String word[] = new String[10];

Also, change word = new String[] { input.next() }; to word[x] = input.next() .

It is also a good idea to move Scanner input = new Scanner(System.in); outside of the for loop. You should read up on how arrays work to make sure this doesn't happen again.

Answer 2

You could try use an ArrayList to do this like so:

import java.util.*;

public class HelloWorld
{
    public static void main(String[] args)
    {
        Scanner sc = new Scanner(System.in);
        ArrayList al = new ArrayList();
        do{
            System.out.println("Enter word");
            String word = sc.nextLine();
            al.add(word);
            if(al.size()==10){
                System.out.println("Words in reverse order");           
                for(int i = al.size()-1; i>= 0; i--){
                    System.out.println(al.get(i));
                }
            }
        }while(al.size()<10);
    }
}

I think this answers your question properly.

All the best

Sean