findIndex

The findIndex() function will return the index number of the first item in a list that matches the condition. If you want to return the item itself, use find.

findIndex(list, condition)

list.findIndex(condition)
Code language: JavaScript (javascript)

Note that lists use zero-based indexing, so 0 will be returned for the first value.

Example Formulas

This formula finds the index of the first item in the list that can be parsed to a date:

[1, "Monkey D. Luffy", true, "2025-01-01", 37, "1999-12-23"].findIndex(
  current.parseDate()
)

/* Output: 3 */
Code language: JavaScript (javascript)

This variation finds the index of the first item that can be parsed to a date and that is before Jan 1, 2000:

[1, "Monkey D. Luffy", true, "2025-01-01", 37, "1999-12-23"].findIndex(
  current.parseDate() < "2000-01-01".parseDate()
)

/* Output: 5 */
Code language: JavaScript (javascript)