About arrays and printing out the newly sorted array?

Question

This is my code for reversing the order of an array:

int array[x];
String temp;

String reversedOrder = "";

for (int i = 0; i < x/2; i++)
 {
 temp = array[i];
 array[i] = array[x-1 - i];
 array[x-1 - i] = temp;
 reversedOrder = reversedOrder + array[i];
 }
System.out.println(reversedOrder);

My question is how to print out this newly sorted array? I try to declare a string and put it in the for loop but it doesnt print the way I wanted it to: lets say "Hello World I am here" I need it to print out "olleHdlroWImaereh" but all it prints are first two reversed words "olleHdlroW" and ends right there.

Any help is appreciated. Thank you.

*I am trying to write this program out on my OWN free time.

*Thanks to everyone for helping me with my program. It finally worked after adding a for loop similar to Elliot's. :p cheers.

Answer 1

First, the easiest way is to use Arrays#toString(). Secondly, there are a few problems with your code,

int[] array = { 1, 2, 3 }; // <-- your array declaration isn't valid.
// String temp; // <-- A String is not an int.
int x = array.length; // <-- added to demonstrate

for (int i = 0; i < x / 2; i++) {
    // This is a swap with no temporary storage, also known as the
    // http://en.wikipedia.org/wiki/XOR_swap_algorithm
    array[i] ^= array[x - 1 - i];
    array[x - 1 - i] ^= array[i];
    array[i] ^= array[x - 1 - i];
}
System.out.println(Arrays.toString(array));

Output is

[3, 2, 1]

EDIT

Remove the Arrays.toString(), and replace it with something like this -

StringBuilder sb = new StringBuilder();
for (int i : array) {
    sb.append(i);
}
System.out.println(sb.toString());

Output is

321

EDIT 2

Or, you could use

for (int i : array) {
    System.out.print(i);
}
System.out.println();

Which will also output

321

Answer 2

Use Arrays class to print user friendly string of array

Arrays.toString(array);

Try this one:

    String[] array = new String[] { "Hello", "World", "I", "am", "here" };

    String[] newArray = new String[array.length];

    for (int i = 0; i < array.length; i++) {
        newArray[array.length - 1 - i] = new StringBuilder(array[i]).reverse().toString();
    }

    System.out.println(Arrays.toString(newArray));

--EDIT--

Use this one to print out array in string format without any commas and brackets

    String str = Arrays.toString(array).replaceAll(", ", "");
    System.out.println(str.substring(1, str.length() - 1));

Answer 3

Your reverse logic looks correct, however you are trying to append your reversedOrder string as you traverse only half of the charArray.

You can get your entire reversed charArray as a String by using the String(char[]) constructor after the for loop.

@Test
public void reverse() {
  char[] charArray = "Hello World I am here".toCharArray();
  int x = charArray.length;

  for (int i = 0; i < x/2; i++) {
    char temp = charArray[i];
    charArray[i] = charArray[x-1 - i];
    charArray[x-1 - i] = temp;
  }

  String expected = "ereh ma I dlroW olleH";
  assertEquals(expected, new String(charArray));
}