Java implementation string inversion

Summarize a common programming topic for Java Interviewing: Reverse the ' abc123 ' string and write down the methods you can think of.

1. Using the reverse member method of StringBuffer or StringBuilder:

  // StringBuffer   Public Static string Reverse1 (String str) {    returnnew  StringBuilder (str). reverse (). ToString ( );  }

2. Use the ToCharArray method of string to first convert the string to a char type array and then re-stitch the individual characters:

  // ToCharArray   Public Static string Reverse2 (String str) {    char[] chars = Str.tochararray ();     = "";      for (int i = chars.length-1; I >= 0; i--) {      + = chars[i]    ;    } return reverse;  }

3. Use the CharAt method of string to remove individual characters from the string:

  // charAt   Public Static string Reverse3 (String str) {    = "";     int length = str.length ();      for (int i = 0; i < length; i++) {      = Str.charat (i) + reverse;    }     return reverse;  }

Finally, add the test code in the Main method:

   Public Static void Main (string[] args) {    = "abc123";    System.out.println ("----------------");      for (int i = s.length ()-1; I >= 0; i--) {      System.out.print (S.charat (i));    }    System.out.println ("----------------");    System.out.println ("before transformation:" + s);    System.out.println ("after transform:" + Reverse1 (s));    System.out.println ("after transform:" + Reverse2 (s));    System.out.println ("after transform:" + Reverse3 (s));  }

Java implementation string inversion