Remove an Element at Specific Index from an Array in Java

Last Updated : 25 Nov, 2024

In Java, removing an element at a specific index from an array means shifting subsequent elements to the left. Arrays have a fixed size, so creating a new array without the target element is often necessary.

Examples:

The basic approach to remove an element at a specific index is using a loop.

Java

// Java program to remove an element // from a specific index from an array  // using loop import java.util.Arrays;  class Main {     public static int[] remove(int[] arr, int in) {          if (arr == null || in < 0 || in >= arr.length) {             return arr;         }        	int[] arr2 = new int[arr.length - 1];          // Copy the elements except the index         // from original array to the other array         for (int i = 0, k = 0; i < arr.length; i++) { 			if (i == in)                 continue; 			           	arr2[k++] = arr[i];         }          return arr2;     }        public static void main(String[] args)     {         int[] arr = { 1, 2, 3, 4, 5 };        	int in = 2;          // Remove the element         arr = remove(arr, in);          System.out.println(Arrays.toString(arr));     } }

Output

[1, 2, 4, 5]

Explanation: This example includes finding the element at the specified index and then removing that element. The rest of the elements are copied into a new array. This would lead to an array of size one less than the original array.

Other Approaches to Remove Element at Specific Index

Using Java 8 Streams

We can use Java 8 streams to remove element at specific index from an array, when modifying small or mid-sized arrays.

Approach:

Get the array and the index.
Convert the array into IntStream using IntStream.range() method.
Remove the specified index element using the filter() method.
Map and form a new array of the filtered elements using map() and toArray() methods.
Return the formed array.

Illustration:

Java

// Java program to remove an element // from a specific index from an array import java.util.Arrays; import java.util.stream.IntStream;  class GFG {     public static int[] remove(int[] arr, int in){ 		if (arr == null || in < 0 || in >= arr.length)             return arr;          return IntStream.range(0, arr.length)             .filter(i -> i != in)             .map(i -> arr[i])             .toArray();     }      public static void main(String[] args)     {         int[] arr = { 1, 2, 3, 4, 5 };         int in = 2;          // Remove the element         arr = remove(arr, in);          System.out.println(Arrays.toString(arr));     } }

Output

[1, 2, 4, 5]

Using ArrayList

We can use ArrayList, if we need flexibility with list operations. It is easier to add or remove elements dynamically before converting back to an array.

Approach:

Get the array and the index.
Form an ArrayList with the array elements.
Remove the specified index element using remove() method.
Form a new array of the ArrayList using mapToInt() and toArray() methods.
Return the formed array.

Illustration:

Java

// Java program to remove an element // from a specific index from an array import java.util.Arrays; import java.util.List; import java.util.stream.Collectors; import java.util.stream.IntStream;  class Main {   	   	// Function to Remove the element from the array   	public static int[] remove(int[] arr, int i){                	if (arr == null || i < 0 || i >= arr.length)             return arr;              	List<Integer> al = IntStream.of(arr).boxed()                                     .collect(Collectors.toList());        	// Removing element from the index         al.remove(i);          return al.stream()             .mapToInt(Integer::intValue)             .toArray();     }      public static void main(String[] args){         int[] arr = { 1, 2, 3, 4, 5 };         int i = 2;        	// Removing index i from arr       	arr = remove(arr, i);          System.out.println(Arrays.toString(arr));     } }

Output

[1, 2, 4, 5]

Using System.arraycopy() method

We can use System.arraycopy() method, when we are dealing with performance-critical applications. It avoids extra object creation and provides efficient array copying specially for large arrays.

Approach:

Get the array and the index.
Create a new array of size one less than the size of the original array.
Copy the elements from starting till index from the original array to the other array using System.arraycopy().
Copy the elements from index + 1 till the end from the original array to the other array using System.arraycopy().
Return the formed array.

Illustration:

Java

// Java program to remove an element // from a specific index from an array  import java.util.Arrays;  class GFG {      // Function to remove the element     public static int[] remove(int[] arr, int i){                if (arr == null || i < 0 || i >= arr.length)             return arr;          int[] arr1 = new int[arr.length - 1];          System.arraycopy(arr, 0, arr1, 0, i);          // Copy the elements from index + 1 till end         // from original array to the other array         System.arraycopy(arr, i + 1,                         arr1, i,                         arr.length - i - 1);          return arr1;     }      public static void main(String[] args){                int[] arr = { 1, 2, 3, 4, 5 }; 		int i = 2;          arr = remove(arr, i);          System.out.println(Arrays.toString(arr));     } }

Output

[1, 2, 4, 5]

How to Add an Element at Particular Index in Java ArrayList?

RishabhPrabhu

Improve

Article Tags :

Practice Tags :

Java

Remove an Element at Specific Index from an Array in Java

Other Approaches to Remove Element at Specific Index

Using Java 8 Streams

Using ArrayList

Using System.arraycopy() method

Similar Reads