Ints toArray() function | Guava | Java
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)); }} |
Output:
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); } }} |
Output:
Exception: java.lang.NullPointerException
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