程序应该做什么:首字母查询相似
- 程序是看两个词具有相同的首个字母。
我想知道是否有人可以帮助调试这个程序。
我认为我做的一切都正确,但是当我尝试运行它时,程序即将出现错误。
我不明白什么是错的。也许我在底部的印刷课,但除此之外,我没有看到任何错误。
import static java.lang.System.*;
import java.util.Scanner;
public class StringFirstLetterCheck
{
String wordOne, wordTwo;
public StringFirstLetterCheck()
{
}
public StringFirstLetterCheck(String one, String two)
{
wordOne = one;
wordTwo = two;
}
public void setWords(String one, String two)
{
wordOne = one;
wordTwo = two;
}
public boolean checkFirstLetter()
{
if (wordOne.charAt(0)== wordTwo.charAt(0));
return true;
}
public String toString()
{
if (wordOne.charAt(0)!= wordTwo.charAt(0))
return wordOne + " does not have the same first letter as " + wordTwo + "\n";
else if (wordOne.charAt(0)== wordTwo.charAt(0))
return wordOne + " does not have same first letter as " + wordTwo + "\n";
return ("wrong");
}
public static void main(String args[])
{
Scanner keyboard = new Scanner(System.in);
out.print("Enter word one :: ");
String a = keyboard.nextLine();
out.print("Enter word two ::");
String b = keyboard.nextLine();
StringFirstLetterCheck test = new StringFirstLetterCheck();
out.print(test);
错误消息:
Exception in thread "main" java.lang.NullPointerException
at StringFirstLetterCheck.toString(StringFirstLetterCheck.java:41)
at java.lang.String.valueOf(Unknown Source)
at java.io.PrintStream.print(Unknown Source)
at StringFirstLetterCheck.main(StringFirstLetterCheck.java:58)
为什么你不帮我们帮你添加你说的错误的文本? – usr2564301
异常在线程 “主” 显示java.lang.NullPointerException \t在StringFirstLetterCheck.toString(StringFirstLetterCheck.java:41) \t在java.lang.String.valueOf(未知来源) \t在java.io.PrintStream.print(未知来源) \t at StringFirstLetterCheck.main(StringFirstLetterCheck.java:58) –
我刚刚看到一个错误,它不能解决其他问题,但如果应该说“确实与第一个字母相同” –