java - 使用 charAt 和 while 循环 Java 在字符串中查找字母
问题描述
我正在尝试制作一个程序来查看用户输入的字母是否在字符串“hello”中,如果是,则打印它在字符串中以及它在字符串中的位置。错误是“二元运算符的错误操作数类型”
String str = "hello", guess;
int testing = 0;
Scanner scan = new Scanner(System.in);
System.out.print("Enter a letter: ");
guess = scan.nextLine(); // Enters a letter
// finds the letter in the string
while (str.charAt(testing) != guess && testing != 6) {
testing++; // Continues loop
}
//prints where letter is if it is in the string
if (str.charAt(testing) == guess)
System.out.println("The letter is at "+testing);
else
System.out.println("Could not find that letter.");
解决方案
您正在尝试将 achar
与 a进行比较String
。
将 achar
与 a进行比较char
:
while (str.charAt(testing) != guess.charAt(0) && testing != 6)
和
if (str.charAt(testing) == guess.charAt(0))
我还会更改您的停止条件以避免StringIndexOutOfBoundsException
找不到匹配项:
while (testing < str.length () && str.charAt(testing) != guess.charAt(0))
和
if (testing < str.length () && str.charAt(testing) == guess.charAt(0))