Array setFloat() method in Java

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

Syntax:

Array.setFloat(Object []array, int index, float 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 float value that is to be set at the given index of the given array.

Return Value : Since this method has a void return type, hence it 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 is the implementation of Array.setFloat() method:

Program 1:

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

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

    // main method
    public static void main(String[] args)
    {
        // Declaring and defining float array
        float f[] = { 1.0f, 2.0f, 3.0f };

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

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

        float value = 4.0f;

        // setFloat method of class Array
        Array.setFloat(f, 1, value);

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

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

Before Set : 1.0 2.0 3.0 
After Set : 1.0 4.0 3.0

Program 2: To demonstrate java.lang.NullPointerException

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

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

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

        try {
            float c = 1.0f;
            // Passing null array as parameter
            Array.setFloat(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 setFloat()
// method of Array class

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

    // main method
    public static void main(String[] args)
    {
        // Declaring and defining float array
        float b[] = { 1.0f, 2.0f, 3.0f };

        try {
            float c = 1.0f;

            // Passing index as 5 in parameter
            // when the size of array is 3
            Array.setFloat(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 setFloat()
// method of Array class

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

    // main method
    public static void main(String[] args)
    {
        // Declaring and defining float variable
        float b = 2.0f;

        try {
            float c = 1.0f;

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

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