slice

The slice() function returns a “slice” or specific section of a list as a new list.

slice(list, number, number [optional])

list.slice(number, number [optional])
Code language: JavaScript (javascript)

It accepts three arguments:

1. The input list.
2. A starting index, which is included in the output string (the start index of the input string is 0).
3. An ending index, which is optional and excluded from the output string.

Example Formulas

[1, 2, 3, 4, 5].slice(2) /* Output: [3, 4, 5] */

["Luffy", "Sanji", "Nami"].slice(1, 2)
/* Output: ["Sanji"] */
Code language: JavaScript (javascript)

For a more complex example, let’s say you’ve got a list of scores. How could you return the first “streak” of scores, each of which is 100 or higher?

lets(
  scores,
  [32, 56, 22, 9, 104, 155, 123, 3, 10, 145, 33, 42],
  startRemoved,
  scores.slice(
    scores.findIndex(current >= 100)
  ),
  startRemoved.slice(
    0, startRemoved.findIndex(current < 100)
  )
)
Code language: JavaScript (javascript)