How to extend an array after initialisation in Java

Problem Description

How to extend an array after initialisation?

Solution

Following example shows how to extend an array after initialization by creating an new array.

public class Main {
   public static void main(String[] args) {
      String[] names = new String[] { "A", "B", "C" };
      String[] extended = new String[5];
      extended[3] = "D";
      extended[4] = "E";
      System.arraycopy(names, 0, extended, 0, names.length);
      
      for (String str : extended){
         System.out.println(str);
      }
   }
}

Result

The above code sample will produce the following result.

A
B
C
D
E

The following is an another Sample example of arrays expansion

public class Main {
   public void extendArraySize() {
      String[] names = new String[] {"Sai", "Ram", "Krishna"};
      String[] extended = new String[5];
      extended[3] = "Prasad";
      extended[4] = "Mammahe";
      System.arraycopy(names, 0, extended, 0, names.length);
      
      for (String str : extended) System.out.println(str);
   } 
   public static void main(String[] args) {
      new Main().extendArraySize();
   }
}

The above code sample will produce the following result.

Sai
Ram
Krishna
Prasad
Mammahe