Skip to content
Related Articles

Related Articles

StringJoiner setEmptyValue() method in Java
  • Difficulty Level : Basic
  • Last Updated : 12 Sep, 2018
GeeksforGeeks - Summer Carnival Banner

The setEmptyValue(CharSequence emptyValue) of StringJoiner sets the sequence of characters to be used when determining the string representation of this StringJoiner and no elements have been added yet, that is, when it is empty. A copy of the emptyValue parameter is made for this purpose. Note that once an add method has been called, the StringJoiner is no longer considered empty, even if the element(s) added correspond to the empty String.

Syntax:

public StringJoiner setEmptyValue(CharSequence emptyValue)

Parameters: This method accepts a mandatory parameter emptyValue which is the characters to return as the value of an empty StringJoiner

Returns: This method returns this StringJoiner itself, so the calls may be chained

Exception: This method throws NullPointerException when the emptyValue parameter is null



Below examples illustrates the setEmptyValue() method:

Example 1:




// Java program to demonstrate
// setEmptyValue() method of StringJoiner
  
import java.util.StringJoiner;
  
public class GFG {
    public static void main(String[] args)
    {
  
        // Create a StringJoiner
        StringJoiner str = new StringJoiner(" ");
  
        // Print the empty StringJoiner
        System.out.println("Initial StringJoiner: "
                           + str);
  
        // Add an emptyValue
        // using setEmptyValue() method
        str.setEmptyValue("StrigJoiner is empty");
  
        // Print the StringJoiner
        System.out.println("After setEmptyValue(): "
                           + str);
  
        // Add elements to StringJoiner
        str.add("Geeks");
        str.add("forGeeks");
  
        // Print the StringJoiner
        System.out.println("Final StringJoiner: "
                           + str);
    }
}
Output:
Initial StringJoiner: 
After setEmptyValue(): StrigJoiner is empty
Final StringJoiner: Geeks forGeeks

Example 2: To demonstrate NullPointerException




// Java program to demonstrate
// setEmptyValue() method of StringJoiner
  
import java.util.StringJoiner;
  
public class GFG {
    public static void main(String[] args)
    {
  
        // Create a StringJoiner
        StringJoiner str = new StringJoiner(" ");
  
        // Print the empty StringJoiner
        System.out.println("Initial StringJoiner: "
                           + str);
  
        try {
            // Add a null emptyValue
            // using setEmptyValue() method
            str.setEmptyValue(null);
        }
        catch (Exception e) {
            System.out.println("Exception when adding null"
                               + " in setEmptyValue(): " + e);
        }
    }
}
Output:
Initial StringJoiner: 
Exception when adding null in setEmptyValue(): 
    java.lang.NullPointerException: 
    The empty value must not be null

Attention reader! Don’t stop learning now. Get hold of all the important Java Foundation and Collections concepts with the Fundamentals of Java and Java Collections Course at a student-friendly price and become industry ready. To complete your preparation from learning a language to DS Algo and many more,  please refer Complete Interview Preparation Course.

My Personal Notes arrow_drop_up
Recommended Articles
Page :