The merge(StringJoiner other) of StringJoiner adds the contents of the given StringJoiner without prefix and suffix as the next element if it is non-empty. If the given StringJoiner is empty, the call has no effect.
Syntax:
public StringJoiner merge(StringJoiner other)
Parameters: This method accepts a mandatory parameter other which is the StringJoiner whose contents should be merged into this one
Returns: This method returns this StringJoiner
Exception: This method throws NullPointerException if the other StringJoiner is null
Below programs illustrate the merge() method:
Example 1: To demonstrate merge() with delimiter ” “
// Java program to demonstrate // merge() method of StringJoiner import java.util.StringJoiner;
public class GFG {
public static void main(String[] args)
{
// Creating StringJoiner with delimiter " "
StringJoiner str1 = new StringJoiner(" ");
// Adding elements in the StringJoiner
str1.add("Geeks");
str1.add(" for ");
str1.add("Geeks");
// Print the StringJoiner
System.out.println("StringJoiner 1 : "
+ str1.toString());
// Creating the second StringJoiner
StringJoiner str2 = new StringJoiner(" ");
str2.add("A");
str2.add("Computer");
str2.add("Portal");
// Print the second StringJoiner
System.out.println("StringJoiner 2 : "
+ str2.toString());
// Merging the StringJoiner using merge()
StringJoiner str = str1.merge(str2);
// Printing the merged StringJoiner
System.out.println("Merged StringJoiner : "
+ str);
}
} |
StringJoiner 1: Geeks for Geeks StringJoiner 2: A Computer Portal Merged StringJoiner : Geeks for Geeks A Computer Portal
Example 2: To demonstrate merge() with delimiter “, “
// Java program to demonstrate // merge() method of StringJoiner import java.util.StringJoiner;
public class GFG1 {
public static void main(String[] args)
{
// Creating StringJoiner with delimiter ", "
StringJoiner str1 = new StringJoiner(", ");
// Adding elements in the StringJoiner
str1.add("Geeks");
str1.add(" for ");
str1.add("Geeks");
// Print the StringJoiner
System.out.println("StringJoiner 1 : "
+ str1.toString());
// Creating the second StringJoiner
StringJoiner str2 = new StringJoiner(", ");
str2.add("A");
str2.add("Computer");
str2.add("Portal");
// Print the StringJoiner
System.out.println("StringJoiner 2 : "
+ str2.toString());
// Merging the StringJoiner using merge()
StringJoiner str = str1.merge(str2);
// Printing the merged StringJoiner
System.out.println("Merged StringJoiner : "
+ str);
}
} |
StringJoiner 1: Geeks, for, Geeks StringJoiner 2: A, Computer, Portal Merged StringJoiner : Geeks, for, Geeks, A, Computer, Portal
Example 3: To demonstrate NullPointerException
// Java program to demonstrate // merge() method of StringJoiner import java.util.StringJoiner;
public class GFG1 {
public static void main(String[] args)
{
// Creating StringJoiner with delimiter ", "
StringJoiner str1 = new StringJoiner(", ");
// Adding elements in the StringJoiner
str1.add("Geeks");
str1.add(" for ");
str1.add("Geeks");
// Print the StringJoiner
System.out.println("StringJoiner 1 : "
+ str1.toString());
// Creating the second StringJoiner
// to be merged as null
StringJoiner str2 = null ;
// Print the StringJoiner
System.out.println("StringJoiner 2 : "
+ str2);
try {
// Merging the StringJoiner using merge()
StringJoiner str = str1.merge(str2);
}
catch (Exception e) {
System.out.println("Exception during merge: "
+ e);
}
}
} |
StringJoiner 1: Geeks, for, Geeks StringJoiner 2: null Exception during merge: java.lang.NullPointerException