我如何在接受各种字符串之前进行代码检查输入

Question

我试图从一组乱七八糟的字母中获取一个有效的单词，但我的代码接受了所有输入（无效的，包括数字）并直接对照单词列表进行检查。我如何根据显示的拼写字母检查输入，以便在检查记录之前只接受包含拼写字母的单词？

import comp102x.IO; //a library from an edx course(COMP 102x)
import java.io.File;
import java.io.IOException;
import java.util.Scanner;
import javax.swing.JOptionPane;
import java.util.Random;

public class FormWords {

public void searchWord() throws IOException

{
            Random random = new Random();
            String [] randAlphs = {"o","b","e","k","a","i","c","d","f","g","h","k","u"};
             int r = random.nextInt(randAlphs.length);
             int a = random.nextInt(randAlphs.length);
             int n = random.nextInt(randAlphs.length);
             int d = random.nextInt(randAlphs.length);
             int o = random.nextInt(randAlphs.length);
             int m = random.nextInt(randAlphs.length);
             int w = random.nextInt(randAlphs.length);
             int i = random.nextInt(randAlphs.length);
             int s = random.nextInt(randAlphs.length);

//prompt's user for input

String answer = JOptionPane.showInputDialog("form words with the following: " + randAlphs[r]+ randAlphs[a]+ randAlphs[n]+ randAlphs[d]+ randAlphs[o]+ randAlphs[m]+ randAlphs[w]+ randAlphs[s]);

/*searches the record to check if input exists
 */
boolean exist = searchFromRecord("record.txt", answer);

if (exist)
{

   JOptionPane.showMessageDialog(null, "Congratulation!The word \"" + answer + "\" is a valid  English word.");
} 
else
{                                        
  // System.out.println("Sorry b ut the word \"" + answer + "\" is not a valid English word.");
  JOptionPane.showMessageDialog(null, "Sorry but the word \"" + answer + "\" is not a valid English word.");
}
}



/**
* Searches the record and returns if a specified word is in the record.
* 
* @param recordName The name of the record text file.
* @param word The word to be searched.
* @return true if the word presents in the record, false otherwise.
*/

private  boolean searchFromRecord(String recordName, String word) throws IOException
{
            // Please write your code after this line
            File inputFile = new File("record.txt");
            Scanner input = new Scanner(inputFile);
            while(input.hasNextLine()){
            if(word.equalsIgnoreCase(input.nextLine())){
                return true;
                }

            }
            return false;

    }


}

Answer 1

在您的 "prompt's user for input" 代码之前。你可以在java中使用和HashSet，把所有的字母都加到de HashSet中。像这样的代码片段：

Set<String> scrabbledLettersSet = new HashSet<String>();
scrabbledLettersSet.add(randAlphs[a]);
scrabbledLettersSet.add(randAlphs[n]);
scrabbledLettersSet.add(randAlphs[d]);
scrabbledLettersSet.add(randAlphs[o]);
scrabbledLettersSet.add(randAlphs[m]);
scrabbledLettersSet.add(randAlphs[w]);
scrabbledLettersSet.add(randAlphs[i]);
scrabbledLettersSet.add(randAlphs[s]);

那么在执行searchFromRecord 方法之前，您可以使用set 来检查您的输入是否有效。代码片段是这样的：

bool containsScrabbledLetters = false;
for(int i = 0 ; i < answer.length() ; ++ i) {
    if (scrabbledLettersSet.contains(answer.substring(i, i + 1))) {
        containsScrabbledLetters = true;
        break;
    }
}

boolean exist = false;
if (containsScrabbledLetters)
    exist = searchFromRecord("record.txt", answer);

以上代码的意思是如果输入字符串中至少有一个字母是拼写字母，则输入OK，如果你的意思是输入字符串中的所有字母都必须存在于拼写字母中，可以使用下面的代码:

bool containsScrabbledLetters = true;
for(int i = 0 ; i < answer.length() ; ++ i) {
    if (!scrabbledLettersSet.contains(answer.substring(i, i + 1))) {
        containsScrabbledLetters = false;
        break;
    }
}

boolean exist = false;
if (containsScrabbledLetters)
    exist = searchFromRecord("record.txt", answer);

我如何在接受各种字符串之前进行代码检查输入

how do i make code check inputs before accepting all kinds of strings

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record