Thread: How to reverse a string array ?

Hello again. I have an array of friends names and I want to print it in reverse. I know this question seems a bit lazy, but i really have tried casting the string as ints and even using lazy = String,valueOf(i) etc but No luck so far. Thanks

 
//FriendList.java
 
public class FriendList  {
 
  public static void main (String[] args)  {
 
  String [] friends = {"danny", "vic", "Laura", "Mike", "Jenny", "Asrath"};
 
  System.out.println ("My first 6 best friends are: ");
 
  for (String lazy : friends)
      System.out.println (lazy + " ");
 
  System.out.println ("Now them in reverse");
 
  //Problems begin here
 
  for (String lazy = friends.length; lazy >= 0; lazy--)
     System.out.println (lazy + " ");
 
  }
}

What should the reverse output look like? I'm not sure what you mean yet.

The first for loop prints : Danny, vic , laura, mike , jenny, asrath.
I want the second for loop to print them in reverse like: asrath, jenny mike, laura, vic. Danny.

The first loop prints the array elements from 0 through 5. The second loop prints the array elements from 5 through 0. Try to code that.

//FriendList.java
 
public class FriendList  {
 
  public static void main (String[] args)  {
 
  String [] friends = {"danny", "vic", "Laura", "Mike", "Jenny", "Asrath"};
 
  System.out.println ("My first 6 best friends are: ");
 
  for (String lazy : friends)
      System.out.println (lazy + " ");
 
  System.out.println ("Now them in reverse");
 
  //Problems begin here
 
  System.out.println (friends[5]);
  System.out.println (friends[4]);
  System.out.println (friends[3]);
  System.out.println (friends[2]);
  System.out.println (friends[1]);
  System.out.println (friends[0]);
 
  }
}

I can't figure out how to do that I can only write them out manually. How do you move down through the array elements ?

The enhanced for loop is a great tool, and I'm impressed that you're using it already, but unfortunately, it only iterates the collection in the forward direction. You'll have to write a loop, usually the standard for loop, to iterate the array in the reverse direction. Can you do that? Can you write a standard for loop in the forward direction? If so, start with that, and think about how you'd write it to go in the reverse direction. If you need help, show what you can do and ask for help.

Well I did it Thanks Greg.

//FriendList.java
 
public class FriendList  {
 
  public static void main (String[] args)  {
 
  String [] friends = {"danny", "vic", "Laura", "Mike", "Jenny", "Asrath"};
 
  System.out.println ("My first 6 best friends are: ");
 
  for (int total = 0; total <= 5; total++)  {
      System.out.println (friends[total]);
  }
 
 
  System.out.println ("Now in reverse");
 
  for ( int total = 5; total >= 0; total--)  {
      System.out.println (friends[total]);
  }
  }
}

Good job! Glad to help, but I didn't do much.

What you are doing is going with a wrong for loop initialization. It will be like this:

public class FriendList  {
 
  public static void main (String[] args)  {
 
  String [] friends = {"danny", "vic", "Laura", "Mike", "Jenny", "Asrath"};
 
  System.out.println ("My first 6 best friends are: ");
 
  for (String lazy : friends)
      System.out.print(lazy + " ");
 System.out.println();
  System.out.println ("Now them in reverse");
 
  //Problems begin here
 
  for (int lazy = (friends.length - 1); lazy >= 0; lazy--)
     System.out.print(friends[lazy] + " ");
 
  }
}