Return an array with the separator interspersed between each element of the input array.
Array to intersperse.
Value to insert.
intersperse(["a", "b", "c"], "x"); // => ["a", "x", "b", "x", "c"] Copy
intersperse(["a", "b", "c"], "x"); // => ["a", "x", "b", "x", "c"]
Return an array with the separator interspersed between each element of the input array.