What is Java Guava | Chars.toArray() method with Examples?

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Java Guava | Chars.toArray() method with Examples️‍🔥

Q: How to use Java Guava | Chars.toArray() method with Examples in JAVA?

The toArray() method of Chars Class in the Guava library is used to convert the char values, passed as the parameter to this method, into a Char Array

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

Syntax:

public static char[] toArray(Collection<Character> collection)

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

Return Value: This method returns a char 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 Chars.toArray() method 
  
import com.google.common.primitives.Chars; 
import java.util.Arrays; 
import java.util.List; 
  
class GFG { 
  
    // Driver's code 
    public static void main(String[] args) 
    { 
  
        // Creating a List of Chars 
        List<Character> myList 
            = Arrays.asList('G', 'E', 'E', 'K', 'S'); 
  
        // Using Chars.toArray() method to convert 
        // a List or Set of Char to an array of Char 
        char[] arr = Chars.toArray(myList); 
  
        // Displaying an array containing each 
        // value of collection, 
        // converted to a char value 
        System.out.println(Arrays.toString(arr)); 
    } 
} 

Output:

[G, E, E, K, S]

Example 2 :

// Java code to show implementation of 
// Guava's Chars.toArray() method 
  
import com.google.common.primitives.Chars; 
import java.util.Arrays; 
import java.util.List; 
  
class GFG { 
  
    // Driver's code 
    public static void main(String[] args) 
    { 
  
        try { 
            // Creating a List of Chars 
            List<Character> myList 
                = Arrays.asList('a', 'b', null); 
  
            // Using Chars.toArray() method 
            // to convert a List or Set of Char 
            // to an array of Char. 
            // This should raise "NullPointerException" 
            // as the collection contains "null" 
            // as an element 
            char[] arr = Chars.toArray(myList); 
  
            // Displaying an array containing each 
            // value of collection, 
            // converted to a char value 
            System.out.println(Arrays 
                                   .toString(arr)); 
        } 
        catch (Exception e) { 
            System.out.println(e); 
        } 
    } 
} 

Output:

java.lang.NullPointerException

Reference :
https://google.github.io/guava/releases/18.0/api/docs/com/google/common/primitives/Chars.html#toArray(java.util.Collection)