Guava’s Ints.toArray() returns an array containing each value of collection, converted to a int value in the manner of Number.intValue()
Syntax:
public static int[] toArray(Collection<? extends Number> collection)
Parameters: This method takes the collection as parameter which is a collection of Number instances.
Return Value: This method returns an array containing the same values as collection, in the same order, converted to primitives.
Exceptions: This method throws NullPointerException if collection or any of its elements is null.
Below examples illustrate the Ints.toArray() method:
Example 1:
// Java code to show implementation of // Guava's Ints.toArray() method import com.google.common.primitives.Ints;
import java.util.Arrays;
import java.util.List;
class GFG {
// Driver's code
public static void main(String[] args)
{
// Creating a List of Integers
List<Integer>
myList = Arrays.asList( 1 , 2 , 3 , 4 , 5 );
// Using Ints.toArray() method to convert
// a List or Set of Integer to an array
// of Int
int [] arr = Ints.toArray(myList);
// Displaying an array containing each
// value of collection,
// converted to a int value
System.out.println( "Array from given List: "
+ Arrays.toString(arr));
}
} |
Array from given List: [1, 2, 3, 4, 5]
Example 2: To demonstrate NullPointerException
// Java code to show implementation of // Guava's Ints.toArray() method import com.google.common.primitives.Ints;
import java.util.Arrays;
import java.util.List;
class GFG {
// Driver's code
public static void main(String[] args)
{
try {
// Creating a List of Integers
List<Integer>
myList = Arrays.asList( 2 , 4 , null );
// Using Ints.toArray() method to convert
// a List or Set of Integer to an array
// of Int. This should raise "NullPointerException"
// as the collection contains "null" as an element
int [] arr = Ints.toArray(myList);
// Displaying an array containing each
// value of collection, converted to a int value
System.out.println(Arrays.toString(arr));
}
catch (Exception e) {
System.out.println( "Exception: " + e);
}
}
} |
Exception: java.lang.NullPointerException