public static boolean isSymmetric(String str) { char[] chArr = str.toCharArray(); int length = chArr.length; //用length/2,可以减少一半的运算,如果是对称字符串的话 for (int i = 0; i < length / 2; i++) { if (chArr[i] != chArr[length - (i + 1)]) { return false; } } return true;