Java Guava | Booleans.toArray() method with Examples

The toArray() method of Booleans Class in the Guava library is used to convert the boolean values, passed as the parameter to this method, into a Boolean Array. These boolean values are passed as a Collection to this method. This method returns a Boolean array.

Syntax:

public static boolean[] toArray(Collection<Boolean> collection)

Parameters: This method accepts a mandatory parameter collection which is the collection of boolean values to be converted in to a Boolean array.

Return Value: This method returns a boolean array containing the same values as a collection, in the same order.

Exceptions: This method throws NullPointerException if the passed collection or any of its elements is null.

Below programs illustrate the use of toArray() method:

Example 1:

// Java code to show implementation of
// Guava's Booleans.toArray() method

import com.google.common.primitives.Booleans;
import java.util.Arrays;
import java.util.List;

class GFG {

    // Driver's code
    public static void main(String[] args)
    {

        // Creating a List of Boolean
        List<Boolean> myList
            = Arrays.asList(false, true,
                            false, false);

        // Using Booleans.toArray() method to convert
        // a List or Set of Boolean to an array
        // of Boolean
        boolean[] arr = Booleans.toArray(myList);

        // Displaying an array containing each
        // value of collection,
        // converted to a boolean value
        System.out.println(Arrays.toString(arr));
    }
}

Output:

[false, true, false, false]

Example 2:

// Java code to show implementation of
// Guava's Booleans.toArray() method

import com.google.common.primitives.Booleans;
import java.util.Arrays;
import java.util.List;

class GFG {

    // Driver's code
    public static void main(String[] args)
    {
        // Creating a List of Boolean
        List<Boolean> myList
            = Arrays.asList(true, true, false);

        // Using Booleans.toArray() method to convert
        // a List or Set of Boolean to an array
        // of Boolean
        boolean[] arr = Booleans.toArray(myList);

        // Displaying an array containing each
        // value of collection,
        // converted to a boolean value
        System.out.println(Arrays.toString(arr));
    }
}

Output:

[true, true, false]

Reference: https://google.github.io/guava/releases/20.0/api/docs/com/google/common/primitives/Booleans.html#toArray-java.util.Collection-