Java String join() with examples

The java.lang.string.join() method concatenates the given elements with the delimiter and returns the concatenated string.Note that if an element is null, then null is added.The join() method is included in java string since JDK 1.8.
There are two types of join() methods in java string.
Syntax:

public static String join(CharSequence deli, CharSequence... ele)  
and  
public static String join
(CharSequence deli, Iterable<? extends CharSequence> ele)     
Parameters:
deli- delimiter to be attached with each element 
ele- string or char to be attached with delimiter
Returns :  string joined with delimiter.

// Java program to demonstrate
// working of join() method

class Gfg1 {
    public static void main(String args[])
    {
        // delimiter is "<" and elements are "Four", "Five", "Six", "Seven"
        String gfg1 = String.join(" < ", "Four", "Five", "Six", "Seven");

        System.out.println(gfg1);
    }
}

Output:

Four < Five < Six < Seven

// Java program to demonstrate
// working of join() method

class Gfg2 {
    public static void main(String args[])
    {
        // delimiter is "  " and elements are "My",
        // "name", "is", "Niraj", "Pandey"
        String gfg2 = String.join("  ", "My", "name", "is", "Niraj", "Pandey");

        System.out.println(gfg2);
    }
}

Output:

My name is Niraj Pandey

// Java program to demonstrate
// working of join() method

class Gfg3 {
    public static void main(String args[])
    {
        // delimiter is "->" and elements are "Wake up",
        // "Eat", "Play", "Sleep", "Wake up"

        String gfg3 = String.join("-> ", "Wake up", "Eat",
                      "Play", "Sleep", "Wake up");

        System.out.println(gfg3);
    }
}

Output:

Wake up-> Eat-> Play-> Sleep-> Wake up