Java Program to insert element to an array at specified position

Program

import java.util.Arrays;
import java.util.Scanner;
public class InsertElementsToArrayAtPosition {
  public static void main(String[] args) {
    int newElement;
    int i, j;
    int position;
    System.out.println("Enter the required size of the array: ");
    Scanner reader = new Scanner(System.in);
    int size = reader.nextInt();
    int inputArray[] = new int[size + 1];
    System.out.println("Enter the elements of the array: ");
    for (i = 0; i < size; i++) {
      inputArray[i] = reader.nextInt();
    }
    System.out.print("Enter the element which you want to insert: ");
    newElement = reader.nextInt();
    System.out.print("Enter the position where you want to insert: ");
    position = reader.nextInt();
    System.out.print("Printing array elements after inserting : ");
    for (j = inputArray.length - 1; j > position; j--) {
      inputArray[j] = inputArray[j - 1];
    }
    inputArray[position] = newElement;
    System.out.println(Arrays.toString(inputArray));
  }
}

This Java program demonstrates how to insert an element into an array at a specified position.

1. Input Array Size and Elements:

   • The user is prompted to input the size of the array (size).
   • An integer array inputArray[] is initialized with a size of size + 1 to allow space for the new element.
   • The user enters the elements of the array, which are stored in the first size positions of inputArray.

2. Input New Element and Position:

   • The user is prompted to input the new element to be inserted (newElement).
   • The user specifies the position (position) where the element should be inserted. This position is 0-based.

3. Shift Elements:

   • To make space for the new element, a for loop iterates backward from the last position (inputArray.length - 1) to the specified position.
   • Each element is shifted one position to the right.

4. Insert Element:

   • The new element is assigned to the specified position in the array.

5. Display Array:

   • The updated array, including the newly inserted element, is printed using Arrays.toString().

Key Points:

• Position Handling:
  • The position must be valid (between 0 and size). Additional validation can be added for error handling.
• Shifting Elements:
  • The shifting operation ensures that no data is overwritten while making space for the new element.
• Static Array:
  • The array size is fixed after creation, and this program works for fixed-sized arrays without using dynamic data structures like ArrayList.

Output

javac InsertElementsToArrayAtPosition.java
java InsertElementsToArrayAtPosition  
Enter the required size of the array: 
3
Enter the elements of the array: 
11
22
44
Enter the element which you want to insert: 33
Enter the position where you want to insert: 2
Printing array elements after inserting : [11, 22, 33, 44]