indexOf method Null safety

int indexOf (
  1. Pattern pattern,
  2. [int start = 0]
)

Returns the position of the first match of pattern in this string, starting at start, inclusive:

var string = 'Dartisans';
string.indexOf('art');                     // 1
string.indexOf(RegExp(r'[A-Z][a-z]')); // 0

Returns -1 if no match is found:

string.indexOf(RegExp(r'dart'));       // -1

The start must be non-negative and not greater than length.

Implementation

int indexOf(Pattern pattern, [int start = 0]);