There are multiple approaches to delete an element from an array at a given location.
We can delete the element from a given index of an array by using a second array, using the java 8 streams () method, or using ArrayList.
For example
Suppose we have an array arr[] = [2, 4, 6, 8, 10]
After deleting the element from index 2 output will be [2, 4, 8, 10]
Here at index 2 there was element 6.
Now lets see the program
Program 1: Delete element from the given index using the second array
- In the below program, we are taking the array elements and array size from the user.
- To delete the element from the given index, we will be using the second array.
- We will be copying the array element from the original array to the new array.
- We are skipping the index from where we have to remove the element and copy the rest array element.
- By doing this in the new array, we are getting all elements except the element which is present at the index that need to delete.
import java.util.*;
public class Main {
public static void main(String[] args) {
int index;
Scanner sc = new Scanner(System.in);
System.out.println("Java Program to delete element from given index");
System.out.print("Enter the size of array: ");
int size = sc.nextInt();
int arr[] = new int[size];
for(int i=0; i<size; i++) {
System.out.print("Please give value for index "+ i +" : ");
arr[i] = sc.nextInt();
}
System.out.println("Enter the index to delete element :");
index=sc.nextInt();
if (arr == null || index < 0
|| index >= arr.length) {
System.out.println(Arrays.toString(arr));
}
int[] arrOutput = new int[arr.length - 1];
for (int i = 0, j = 0; i < arr.length; i++) {
if (i == index) {
continue;
}
arrOutput[j++] = arr[i];
}
System.out.println("Resultant Array: "
+ Arrays.toString(arrOutput));
}
}Output
Java Program to delete element from given index
Enter the size of array: 5
Please give value for index 0 : 2
Please give value for index 1 : 4
Please give value for index 2 : 1
Please give value for index 3 : 5
Please give value for index 4 : 6
Enter the index to delete element :
2
Resultant Array: [2, 4, 5, 6]Program 2 : Delete an element from a given index using Arraylist
- Here we are taking the help of remove() function of arraylist.
- First we are taking the array size and array input.
- We are converting array into arraylist to use the remove() function of array list.
import java.util.stream.Collectors;
import java.util.*;
class Main {
public static void main(String[] args)
{
Scanner sc = new Scanner(System.in);
System.out.println("Java Program to delete element from given index");
System.out.print("Enter the size of array: ");
int size = sc.nextInt();//taking array size from users
int arr[] = new int[size]; //creating array of given size
for(int i=0; i<size; i++) {
System.out.print("Please give value for index "+ i +" : ");
arr[i] = sc.nextInt(); //taking values at each index of array
}
System.out.println("Original Array: " + Arrays.toString(arr));
System.out.println("Enter the index to delete element :");
int index=sc.nextInt(); //taking index from users to perform delete
//converting array into arraylist
List<Integer> arrayList = Arrays.stream( arr ).boxed().collect( Collectors.toList() );
arrayList.remove(index); //removing value from given index
System.out.println("Array after performing delete operation: "
+ Arrays.toString(arrayList.toArray())); //printing the new Resultant array
}
}Output
Java Program to delete element from given index
Enter the size of array: 5
Please give value for index 0 : 3
Please give value for index 1 : 1
Please give value for index 2 : 4
Please give value for index 3 : 2
Please give value for index 4 : 5
Enter the index to delete element :
3
Array After removing element from given location:
[3, 1, 4, 5]Program 3: Using JAVA 8 Stream API
- Here we are getting array size and array inputs from the users.
- Using IntStream.range() we are converting input array into IntStream.
- With the help of filter() method we are removing array elements.
- Once the element has remove from the array using filter() method, printing the result using Arrays.toString(result).
import java.util.stream.Collectors;
import java.util.stream.IntStream;
import java.util.*;
class Main {
public static void main(String[] args)
{
Scanner sc = new Scanner(System.in);
System.out.println("Java Program to delete element from given index");
System.out.print("Enter the size of array: ");
//taking array size from users
int size = sc.nextInt();
//creating array of given size
int arr[] = new int[size];
for(int i=0; i<size; i++) {
System.out.print("Please give value for index "+ i +" : ");
//taking values at each index of array
arr[i] = sc.nextInt();
}
System.out.println("Original Array: " + Arrays.toString(arr));
System.out.println("Enter the index to delete element :");
//taking index from users to perform delete
int index=sc.nextInt();
int result[]=IntStream.range(0, arr.length)
.filter(i -> i != index)
.map(i -> arr[i])
.toArray();
//printing the new Resultant array
System.out.println("Array after performing delete operation: "
+ Arrays.toString(result));
}
}Output
Please give value for index 0 : 3
Please give value for index 1 : 1
Please give value for index 2 : 5
Please give value for index 3 : 2
Please give value for index 4 : 7
Original Array: [3, 1, 5, 2, 7]
Enter the index to delete element :
3
Array after performing delete operation: [3, 1, 5, 7]
