ABC输出BCA

public class TestString {
public static String reverse(String s) {
char[] c = new char[s.length()];
for (int i = 0; i < s.length(); i++)
c[i] = s.charAt(s.length() - 1 - i);
return String.valueOf(c);
}

public static void main(String[] args) {
String s = "abcd";
s = reverse(s);
System.out.println(s);

}
}