Array setLong() method in Java

The java.lang.reflect.Array.setLong() is an inbuilt method in Java and is used to set a specified long value to a specified index of a given object array.

Syntax:

Array.setLong(Object []array, int index, long value)

Parameter:

• array : This is an array of type Object which is to be updated.
• index : This is the index of the array which is to be updated.
• value : This is the long value that is to be set at the given index of the given array.

Return type: This is a void type method which doesn’t returns any value. The update reflects upon the Object array passed as the argument.

Exception: This method throws following exceptions.

• NullPointerException – when the array is null.
• IllegalArgumentException – when the given object array is not an Array.
• ArrayIndexOutOfBoundsException – if the given index is not in the range of the size of the array.

Below programs illustrate the Array.setLong() method:

Program 1 :

// Java code to demonstrate setLong() method of Array class
import java.lang.reflect.Array;
public class GfG {
    // main method
    public static void main(String[] args)
    {

        // Declaring and defining long array
        long b[] = { 1, 2, 3, 4 };
        System.out.print("Before Set : ");
        // printing the array
        for (long x : b) {
            System.out.print(x + " ");
        }
        long value = 10;
        // setLong method of class Array
        Array.setLong(b, 1, value);

        System.out.print("\nAfter Set : ");
        // printing array
        for (Long x : b) {
            System.out.print(x + " ");
        }
    }
}

Output

Before Set : 1 2 3 4 
After Set : 1 10 3 4 

Program 2 : To demonstrate java.lang.NullPointerException

// Java code to demonstrate setLong() method of Array class
import java.lang.reflect.Array;
public class GfG {
    // main method
    public static void main(String[] args)
    {

        // Declaring and defining long array to null
        long b[] = null;
        try {
            Array.setLong(b, 5, 10);
        }
        catch (Exception e) {
            System.out.println("Exception : " + e);
        }
    }
}

Output

Exception : java.lang.NullPointerException

Program 3 : To demonstrate java.lang.ArrayIndexOutOfBoundsException

// Java code to demonstrate setLong() method of Array class
import java.lang.reflect.Array;
public class GfG {
    // main method
    public static void main(String[] args)
    {

        // Declaring and defining long array
        long b[] = { 1, 2, 3, 4 };
        try {
            Array.setLong(b, 5, 10);
        }
        catch (Exception e) {
            System.out.println("Exception : " + e);
        }
    }
}

Output

Exception : java.lang.ArrayIndexOutOfBoundsException

Program 4 : To demonstrate java.lang.IllegalArgumentException.

// Java code to demonstrate setLong() method of Array class

import java.lang.reflect.Array;
public class GfG {
    // main method
    public static void main(String[] args)
    {

        // Declaring and defining long variable
        long b = 1;
        try {
            Array.setLong(b, 5, 10);
        }
        catch (Exception e) {
            System.out.println("Exception : " + e);
        }
    }
}

Output

Exception : java.lang.IllegalArgumentException: Argument is not an array