java - 从文本文件中线性搜索字符串数组中的单词

Question

这个问题已经有答案了:

How do I compare strings in Java? (23 个回答)

已关闭 6 年前。

我试图弄清楚如何读取文本文件中的字符串列表并返回找到的单词的位置。我不知道为什么这不起作用。有人可以告诉我我做错了什么吗？它为每个单词返回 -1，并且这些单词肯定在其中。

public class LinearSearch extends SearchAlgorithm
{
public int search(String[] words, String wordToFind) throws ItemNotFoundException {
    for (int i = 0; i < words.length; i++) {
        if (words[i] == wordToFind) {
            return i;
        }
        else {
            return -1;
        }
    }
    return -1;
}

public final static String FILE_AND_PATH = "longwords.txt";
/* 
 * TODO: Be sure to change the FILE_AND_PATH to point to your local 
 * copy of longwords.txt or a FileNotFoundException will result
 */ 


//Note how we deal with Java's Catch-or-Declare rule here by declaring the exceptions we might throw
public static void main(String[] args) throws FileNotFoundException {
    File file = new File("/Users/myName/Desktop/compsci/HOMEWORK/recursion/longwords.txt");
    Scanner input = new Scanner(file);
    int wordCount = 0;
    ArrayList<String> theWords = new ArrayList<String>();

    //read in words, count them
    while(input.hasNext())  {
        theWords.add( input.next() );
        wordCount++;
    }

    //make a standard array from an ArrayList
    String[] wordsToSearch = new String[theWords.size()];
    theWords.toArray(wordsToSearch);

    //start with the linear searches
    tryLinearSearch(wordsToSearch, "DISCIPLINES");
    tryLinearSearch(wordsToSearch, "TRANSURANIUM");
    tryLinearSearch(wordsToSearch, "HEURISTICALLY");
    tryLinearSearch(wordsToSearch, "FOO");

Answer 1

您不能将字符串与 words[i] == wordToFind 进行比较。您必须使用words[i].equals(wordToFind)。

您还应该删除 for 循环中的 else block 。