我为 COSC 课程制作的这个程序编译不正确,我不断收到错误消息:
线程“主”java.lang.StringIndexOutOfBoundsException 中的异常:字符串索引超出范围:2
在 java.lang.String.substring(String.java:1765) 在 VowelCount.main(VowelCount.java:13)
这是我的代码:
import java.util.Scanner;
public class VowelCount {
public static void main(String[] args) {
int a = 0, e = 0, i = 0, o = 0, u = 0, count = 0;
String input, letter;
Scanner scan = new Scanner (System.in);
System.out.println ("Please enter a string: ");
input = scan.nextLine();
while (count <= input.length() ) {
letter = input.substring(count, (count + 1));
if (letter == "a") {
a++; }
if (letter == "e") {
e++; }
if (letter == "i") {
i++; }
if (letter == "o") {
o++; }
if (letter == "u") {
u++; }
count++;
}
System.out.println ("There are " + a + " a's.");
System.out.println ("There are " + e + " e's.");
System.out.println ("There are " + i + " i's.");
System.out.println ("There are " + o + " o's.");
System.out.println ("There are " + u + " u's.");
}
}
据我所知,这应该有效,但为什么不呢?任何帮助都会很棒。谢谢!