Given a primitive array, the task is to get a slice of the array using the start and end index in Java.

Examples:

Input: arr[] = {1, 2, 3, 4, 5}, startIndex = 2, endIndex = 4
Output: {3, 4, 5}

Input: arr[] = {1, 2, 3, 4, 5}, startIndex = 0, endIndex = 1
Output: {1, 2}

Method 1: Naive Method.

1. Get the Array and therefore the refore the startIndex and the endIndex.
2. Create and empty primitive array of size endIndex-startIndex.
3. Copy the weather from startIndex to endIndex from the first array to the slice array.
4. Return or print the slice of the array.

Below is the implementation of the above approach:

// Java program to Get a Slice
// of a Primitive Array

import java.util.Arrays;

class GFG {
	// Function to get slice of a primitive array in Java
	public static int[] getSliceOfArray(int[] arr,
									int start, int end)
	{

		// Get the slice of the Array
		int[] slice = new int[end - start];

		// Copy elements of arr to slice
		for (int i = 0; i < slice.length; i++) {
			slice[i] = arr[start + i];
		}

		// return the slice
		return slice;
	}
	public static void main(String[] args)
	{

		// Get the array, startIndex and endIndex
		int[] arr = { 1, 2, 3, 4, 5 };
		int start = 2, end = 4;

		// Get the slice of the array
		int[] slice = getSliceOfArray(arr, start, end + 1);

		// Print the slice of the array
		System.out.println(Arrays.toString(slice));
	}
}

Output:

[3, 4, 5]

Method 2: Using Arrays.copyOfRange() method.

1. Get the Array and therefore the refore the startIndex and the endIndex.
2. Get the slice using Arrays.copyOfRange() method.
3. Return or print the slice of the array.

Below is the implementation of the above approach:

// Java program to Get a Slice
// of a Primitive Array

import java.util.Arrays;

class GFG {
	// Function to get slice of a primitive array in Java
	public static int[] getSliceOfArray(int[] arr,
							int startIndex, int endIndex)
	{

		// Get the slice of the Array
		int[] slice = Arrays
						.copyOfRange(

							// Source
							arr,

							// The Start index
							startIndex,

							// The end index
							endIndex);

		// return the slice
		return slice;
	}
	public static void main(String[] args)
	{

		// Get the array, startIndex and endIndex
		int[] arr = { 1, 2, 3, 4, 5 };
		int start = 2, end = 4;

		// Get the slice of the array
		int[] slice = getSliceOfArray(arr, start, end + 1);

		// Print the slice of the array
		System.out.println(Arrays.toString(slice));
	}
}

Output:

[3, 4, 5]

Method 3: Using Java 8 Streams

1. Get the Array and therefore the refore the startIndex and the endIndex.
2. Convert the required range of elements from the startIndex to endIndex to Primitive Stream using range() method.
3. Map the required elements from the first array using map() method.
4. Convert the mapped array into array using toArray() method.
5. Return or print the slice of the array.

Below is the implementation of the above approach:

// Java program to Get a Slice
// of a Primitive Array

import java.util.Arrays;
import java.util.stream.IntStream;

class GFG {

	// Function to get slice of a primitive array in Java
	public static int[] getSliceOfArray(int[] arr,
							int startIndex, int endIndex)
	{

		// Get the slice of the Array
		int[] slice = IntStream

						// Convert the specified elements
						// of array into IntStream
						.range(startIndex, endIndex)

						// Lambda expression to get
						// the elements of IntStream
						.map(i -> arr[i])

						// Convert the mapped elements
						// into the slice array
						.toArray();

		// return the slice
		return slice;
	}
	public static void main(String[] args)
	{

		// Get the array, startIndex and endIndex
		int[] arr = { 1, 2, 3, 4, 5 };
		int start = 2, end = 4;

		// Get the slice of the array
		int[] slice = getSliceOfArray(arr, start, end + 1);

		// Print the slice of the array
		System.out.println(Arrays.toString(slice));
	}
}

Output:

[3, 4, 5]