Array join() Method

Array to string conversion in JavaScript is achieved using the join() method. The JavaScript Array join() method joins all elements of an array and converts into a single string. The syntax is


			array.join(separator)

The optional separator parameter is some character to separate each element of the array in the returned string.

Consider the array ["Debian", "Fedora", "openSUSE", "Ubuntu"]. If we apply the typeof operator on it,


			> typeof ["Debian", "Fedora", "openSUSE", "Ubuntu"]; // object

it will return the string value "object". If the array calls the join() method, the typeof operator applied on it


			> typeof ["Debian", "Fedora", "openSUSE", "Ubuntu"].join(); // string

will return the value "string".

We assign the above array to the variable os and call the join() method,


			> var os = ["Debian", "Fedora", "openSUSE", "Ubuntu"];
			> console.log(os.join());

which gives us a string of all elements of the array joined together, separated by a comma as a delimiter


			Debian,Fedora,openSUSE,Ubuntu

Separator

If we pass the asterisk character (*) as an argument into the join() method


				> var os = ["Debian", "Fedora", "openSUSE", "Ubuntu"];
				> console.log(os.join('*'));

the resulting output in the browser console is a single string of joined array elements separated by the asterisk character (*) as a delimiter


				Debian*Fedora*openSUSE*Ubuntu