Reverse string array in java

Let’s learn reverse string array in java.

Reverse string array in java

Here’s the reverse string array program using for loop.

import java.util.Arrays;
public class ReverseStringArrayInJava
{
   public static void main(String[] args)
   {
      String[] strHierarchy = new String[]{"Junior Developer","Senior Developer","Team Lead","Project Manager","Senior Manager","CEO"};
      System.out.println("Given string array: " + Arrays.toString(strHierarchy));
      for(int a = 0; a < strHierarchy.length / 2; a++)
      {
         String strTemp = strHierarchy[a];
         strHierarchy[a] = strHierarchy[strHierarchy.length - a - 1];
         strHierarchy[strHierarchy.length - a - 1] = strTemp;
      }
      System.out.println("Reversed string array: ");
      for(int a = 0; a < strHierarchy.length; a++)
      {
         System.out.println(strHierarchy[a]);
      }
   }
}

Output:

Given string array: [Junior Developer, Senior Developer, Team Lead, Project Manager, Senior Manager, CEO]
Reversed string array:
CEO
Senior Manager
Project Manager
Team Lead
Senior Developer
Junior Developer

Reversing a string array using Arrays.asList() method

To reverse a string array we can use ArrayList.asList() method.

import java.util.Arrays;
import java.util.Collections;
public class ReverseStringArrayUsingFunction
{
   // function to reverse elements of string array
   static void reverseString(String myArray[])
   {
      Collections.reverse(Arrays.asList(myArray));
      System.out.println("Reversed String Array : " + Arrays.asList(myArray));
   }
   public static void main(String[] args)
   {
      String[] myArray = {"eleven", "twelve", "thirteen", "fourteen", "fifteen"};
      System.out.println("Given Array: " + Arrays.asList(myArray));
      reverseString(myArray);
   }
}

Output:

Given Array: [eleven, twelve, thirteen, fourteen, fifteen]
Reversed String Array : [fifteen, fourteen, thirteen, twelve, eleven]

Reverse array in java using Collections.reverse() method

Collections.reverse() method reverses the order of the elements in the specified list. reverse() method throws UnsupportedOperationException if the specified list or its list-iterator does not support the set operation.

Now let’s see an example on reverse array in java using Collections.reverse() method.

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
public class ReverseStringArrayUsingCollections
{
   public static void main(String[] args)
   {
      // creating list of strings
      List<String> li = new ArrayList<String>();
      li.add("java");
      li.add("core");
      li.add("world");
      li.add("hello");
      System.out.println("Given list: " + li);
      Collections.reverse(li);
      System.out.println("After using collections: " + li);
   }
}

Output:

Given list: [java, core, world, hello]
After using collections: [hello, world, core, java]

Arrays class do not have reverse() method. So to reverse an array use Collections.reverse() method.

import java.util.Arrays;
import java.util.Collections;
public class ReverseArrayUsingCollections
{
   public static void main(String[] args)
   {
      Integer[] arr = {2, 4, 6, 8, 10};
      System.out.println("Given array: " + Arrays.toString(arr));
      Collections.reverse(Arrays.asList(arr));
      System.out.println("After using collections: " + Arrays.toString(arr));
   }
}

Output:

Given array: [2, 4, 6, 8, 10]
After using collections: [10, 8, 6, 4, 2]

So this is all about how to reverse a string array. I hope you have understood the concept of reversing a string array in java.