W3School TIY Editor

public class Main { public static void main(String[] args) { String originalStr = "Hello"; String reversedStr = ""; System.out.println("原始字符串: " + originalStr); for (int i = 0; i < originalStr.length(); i++) { reversedStr = originalStr.charAt(i) + reversedStr; } System.out.println("反转后字符串: "+ reversedStr); } }