lastIndexOf method Null safety

int lastIndexOf (
  1. Pattern pattern,
  2. [int? start]

Returns the starting position of the last match pattern in this string, searching backward starting at start, inclusive:

var string = 'Dartisans';
string.lastIndexOf('a');                    // 6
string.lastIndexOf(RegExp(r'a(r|n)'));      // 6

Returns -1 if pattern could not be found in this string.

string.lastIndexOf(RegExp(r'DART'));        // -1

If start is omitted, search starts from the end of the string. If supplied, start must be non-negative and not greater than length.


int lastIndexOf(Pattern pattern, [int? start]);