Array setChar() method in Java

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

Syntax:

Array.setChar(Object []array, int index, char value)

Parameter: This method takes three parameters:

• 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 char value that is to be set at the given index of the given array.

Return Value: This method has a void return type. Hence this doesn’t returns any value. The update reflects upon the Object array passed as the argument.

Exceptions: This method throws following exception:

• 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 is the implementation of Array.setChar() method:

Program 1:

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

import java.lang.reflect.Array;

public class GfG {

    // main method
    public static void main(String[] args)
    {
        // Declaring and defining char array
        char ch[] = { 'a', 'b', 'c', 'd', 'e' };

        System.out.print("Before Set : ");

        // printing the array
        for (char x : ch) {
            System.out.print(x + " ");
        }

        char value = 'g';

        // setChar method of class Array
        Array.setChar(ch, 1, value);

        System.out.print("\nAfter Set : ");

        // printing array
        for (char x : ch) {
            System.out.print(x + " ");
        }
    }
}
Output:

Before Set : a b c d e 
After Set : a g c d e

Program 2: To demonstrate java.lang.NullPointerException

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

import java.lang.reflect.Array;

public class GfG {

    // main method
    public static void main(String[] args)
    {
        // Declaring and defining char array to null
        char b[] = null;

        try {
            char c = 'a';

            // Passing null array in parameter
            Array.setChar(b, 5, c);
        }
        catch (Exception e) {
            System.out.println("Exception : " + e);
        }
    }
}
Output:

Exception : java.lang.NullPointerException

Program 3: To demonstrate java.lang.ArrayIndexOutOfBoundsException

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

import java.lang.reflect.Array;
public class GfG {

    // main method
    public static void main(String[] args)
    {
        // Declaring and defining char array
        char b[] = { 'a', 'b', 'c', 'd' };

        try {
            char c = 'g';
            // Passing index 5 as parameter
            // when the size is 4 instead
            Array.setChar(b, 5, c);
        }
        catch (Exception e) {
            System.out.println("Exception : " + e);
        }
    }
}
Output:

Exception : java.lang.ArrayIndexOutOfBoundsException

Program 4: To demonstrate java.lang.IllegalArgumentException

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

import java.lang.reflect.Array;
public class GfG {

    // main method
    public static void main(String[] args)
    {
        // Declaring and defining char variable
        char b = 'b';

        try {
            char c = 'g';

            // Passing a variable as parameter
            // when an array is expected instead
            Array.setChar(b, 5, c);
        }
        catch (Exception e) {
            System.out.println("Exception : " + e);
        }
    }
}
Output:

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