FloatBuffer hasArray() method in Java with Examples

The hasArray() method of java.nio.FloatBuffer class is used to ensure whether or not the given buffer is backed by an accessible float array. It returns true if there is an accessible backing array to this buffer, else it returns false. If this method returns true, then the array() and arrayOffset() methods may safely be invoked, as they work on the backing array. Syntax :

public final boolean hasArray()

Returns: This method will return true if, and only if, this buffer is backed by an array and is not read-only. Else it returns false. Below are the examples to illustrate the hasArray() method: Examples 1: When the buffer is backed by an array

Java

// Java program to demonstrate
// hasArray() method

import java.nio.*;
import java.util.*;

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

        // Declaring the capacity of the FloatBuffer
        int capacity = 10;

        // Creating the FloatBuffer
        try {

            // creating object of floatbuffer
            // and allocating size capacity
            FloatBuffer fb = FloatBuffer.allocate(capacity);

            // putting the value in floatbuffer
            fb.put(8.56F);
            fb.put(2, 9.61F);
            fb.rewind();

            // checking FloatBuffer fb is backed by array or not
            boolean isArray = fb.hasArray();

            // checking if else condition
            if (isArray)
                System.out.println("FloatBuffer fb is"
                                   + " backed by array");
            else
                System.out.println("FloatBuffer fb is"
                                   + " not backed by any array");
        }

        catch (IllegalArgumentException e) {
            System.out.println("IllegalArgumentException catched");
        }

        catch (ReadOnlyBufferException e) {
            System.out.println("ReadOnlyBufferException catched");
        }
    }
}

Output:

FloatBuffer fb is backed by array

Examples 2: When the buffer is backed by an array

Java

// Java program to demonstrate
// hasArray() method

import java.nio.*;
import java.util.*;

public class GFG {

    public static void main(String[] args)
    {

        // Declaring the capacity of the FloatBuffer
        int capacity = 10;

        // Creating the FloatBuffer
        try {

            // creating object of floatbuffer
            // and allocating size capacity
            FloatBuffer fb = FloatBuffer.allocate(capacity);

            // putting the value in floatbuffer
            fb.put(8.56F);
            fb.put(2, 9.61F);
            fb.rewind();

            // Creating a read-only copy of FloatBuffer
            // using asReadOnlyBuffer() method
            FloatBuffer fb1 = fb.asReadOnlyBuffer();

            // checking FloatBuffer fb is backed by array or not
            boolean isArray = fb1.hasArray();

            // checking if else condition
            if (isArray)
                System.out.println("FloatBuffer fb is"
                                   + " backed by array");
            else
                System.out.println("FloatBuffer fb is"
                                   + " not backed by any array");
        }

        catch (IllegalArgumentException e) {
            System.out.println("IllegalArgumentException catched");
        }

        catch (ReadOnlyBufferException e) {
            System.out.println("ReadOnlyBufferException catched");
        }
    }
}

Output:

FloatBuffer fb is not backed by any array

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