Reverser

//字母逆序

public static String letterReverse(String str) {

    String str2 = "";

    for (int i = str.length() - 1; i > -1; i--) {

        str2 += String.valueOf(str.charAt(i));

    }

    return str2;

}

//单词逆序

public static String wordReverse(String str){

    String str2 = "";

    String[] s = str.split(" ");

    for(int i = s.length - 1; i > -1; i--){

        str2 += String.valueOf(s[i]) + " ";

    }

    return str2;

}