indexWhere method Null safety

int indexWhere (
  1. bool test(
    1. E element
    ),
  2. [int start = 0]
)

The first index in the list that satisfies the provided test.

Searches the list from index start to the end of the list. The first time an object o is encountered so that test(o) is true, the index of o is returned.

var notes = ['do', 're', 'mi', 're'];
notes.indexWhere((note) => note.startsWith('r'));       // 1
notes.indexWhere((note) => note.startsWith('r'), 2);    // 3

Returns -1 if element is not found.

notes.indexWhere((note) => note.startsWith('k'));    // -1

Implementation

int indexWhere(bool test(E element), [int start = 0]);