JS Practice — Built-in Objects

Array.prototype.join() — default separator

📖 Usage Example

const arr = [1, 2, 3]
arr.join()    // → '1,2,3'  (default separator is ',')
arr.toString() // → '1,2,3'  (same result)

Calling join() without arguments uses a comma as the default separator.

Array.prototype.join() — default comma separator

When called with no arguments, join() uses a comma (,) as the separator — with no space.

Challenge: Implement joinDefault(arr) that calls arr.join() with no separator argument.

joinDefault([1, 2, 3]) // → '1,2,3'
joinDefault([])        // → ''

💡 Hints (2)