Arrays.copyOfRange(int[], int, int) in Java

Arrays.copyOfRange(int[], int, int): This method is available in java.util.Arrays class of Java

Syntax:

int[] java.util.Arrays.copyOfRange(int[] original, int from, int to)

This method takes three arguments one of type int array and the rest two are of type int as its parameters. This method copies the specified range of the specified array into a new array.

Parameters: Three parameters are required for this method.

original: the array from which a range is to be copied.

from: the initial index of the range to be copied, inclusive.

to: the final index of the range to be copied, exclusive.

Returns: a new array containing the specified range from the original array, truncated or padded with zeros to obtain the required length.

Throws:

1. ArrayIndexOutOfBoundsException - if from < 0or from > original.length.

2. IllegalArgumentException - if from > to.

3. NullPointerException - if original is null.

Approach 1: When no exceptions.

Java

import java.util.Arrays;

public class ArrayscopyOfRangeint {
    public static void main(String[] args) {

        int orininal[] = { 1, 2, 3, 4 };
        int from = 0, to = 2;
        System.out.println(Arrays.toString(Arrays.copyOfRange(orininal,
                           from, to)));
    }
}

Output:

[1, 2]

Approach 2: ArrayIndexOutOfBoundsException

Java

import java.util.Arrays;

public class ArrayscopyOfRangefloat {
    public static void main(String[] args) {

        int orininal[] = { 1, 2, 3, 4 };
        int from = -1, to = 2;
        System.out.println(Arrays.toString(Arrays.copyOfRange(orininal,
                                                  from, to)));
    }
}

Output:

Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: arraycopy: source index -1 out of bounds for int[4]
	at java.base/java.lang.System.arraycopy(Native Method)
	at java.base/java.util.Arrays.copyOfRange(Arrays.java:3894)
	

Approach 3: IllegalArgumentException 

Java

import java.util.Arrays;

public class ArrayscopyOfRangefloat {
    public static void main(String[] args) {

        int orininal[] = { 1, 2, 3, 4 };
        int from = 4, to = 2;
        System.out.println(Arrays.toString(Arrays.copyOfRange(orininal, 
                                                      from, to)));
    }
}

Output:

Exception in thread "main" java.lang.IllegalArgumentException: 4 > 2
	at java.base/java.util.Arrays.copyOfRange(Arrays.java:3892)
	

Approach 4: NullPointerException 

Java

import java.util.Arrays;

public class ArrayscopyOfRangefloat {
    public static void main(String[] args) {

        int orininal[] = null;
        int from = 0, to = 2;
        System.out.println(Arrays.toString(Arrays.copyOfRange(orininal,
                                                   from, to)));
    }
}

Output:

Exception in thread "main" java.lang.NullPointerException: Cannot read the array length because "original" is null
	at java.base/java.util.Arrays.copyOfRange(Arrays.java:3894)