Slices

Array Slicing and Splicing with Ranges

Ranges can also be used to extract slices of arrays. With two dots (3..6), the range is inclusive (3, 4, 5, 6); with three dots (3...6), the range excludes the end (3, 4, 5). Slices indices have useful defaults. An omitted first index defaults to zero and an omitted second index defaults to the size of the array.

codeFor('slices', 'middle')

The same syntax can be used with assignment to replace a segment of an array with new values, splicing it.

codeFor('splices', 'numbers')

Note that JavaScript strings are immutable, and can’t be spliced.