Convert array to a string

Array.join(separator) can be used to output an array as a string, with a configurable separator.

Default (separator = “,”):

["a", "b", "c"].join() === "a,b,c"

With a string separator:

[1, 2, 3, 4].join(" + ") === "1 + 2 + 3 + 4"

With a blank separator:

["B", "o", "b"].join("") === "Bob"