Given an array of size n, the task is to add an element x in this array in Java. The size of the array cannot be changed dynamically in Java, as it is done in C/C++. Hence in order to add an element in the array, one of the following methods can be done:
- By creating a new array:
- Create a new array of size n+1, where n is the size of the original array.
- Add the n elements of the original array in this array.
- Add the new element in the n+1 th position.
- Print the new array.
Below is the implementation of the above approach:
Java
// Java Program to add an element in an Array import java.io.*;import java.lang.*;import java.util.*; class GFG { // Function to add x in arr public static int[] addX(int n, int arr[], int x) { int i; // create a new array of size n+1 int newarr[] = new int[n + 1]; // insert the elements from // the old array into the new array // insert all elements till n // then insert x at n+1 for (i = 0; i < n; i++) newarr[i] = arr[i]; newarr[n] = x; return newarr; } // Driver code public static void main(String[] args) { int n = 10; int i; // initial array of size 10 int arr[] = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 }; // print the original array System.out.println("Initial Array:\n" + Arrays.toString(arr)); // element to be added int x = 50; // call the method to add x in arr arr = addX(n, arr, x); // print the updated array System.out.println("\nArray with " + x + " added:\n" + Arrays.toString(arr)); }} |
Output: Initial Array: [1, 2, 3, 4, 5, 6, 7, 8, 9, 10] Array with 50 added: [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 50]
Time Complexity: O(N)
Auxiliary Space: O(N)
- By using ArrayList as intermediate storage:
- Create an ArrayList with the original array, using asList() method.
- Simply add the required element in the list using add() method
- Convert the list to an array using toArray() method
Java
// Java Program to add an element in an Array import java.io.*; import java.lang.*; import java.util.*; class GFG { // Function to add x in arr public static Integer[] addX(int n, Integer arr[], int x) { int i; // create a new ArrayList List<Integer> arrlist = new ArrayList<Integer>( Arrays.asList(arr)); // Add the new element arrlist.add(x); // Convert the Arraylist to array arr = arrlist.toArray(arr); // return the array return arr; } // Driver code public static void main(String[] args) { int n = 10; int i; // initial array of size 10 Integer arr[] = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 }; // print the original array System.out.println("Initial Array:\n" + Arrays.toString(arr)); // element to be added int x = 50; // call the method to add x in arr arr = addX(n, arr, x); // print the updated array System.out.println("\nArray with " + x + " added:\n" + Arrays.toString(arr)); } } |
Output: Initial Array: [1, 2, 3, 4, 5, 6, 7, 8, 9, 10] Array with 50 added: [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 50]
Time Complexity: O(N)
Auxiliary Space: O(N)
