is in string flutter code example

Example 1: flutter string contains

var string = 'Dart strings';
string.contains('D');                     // true
//You can use Regex to find patterns inside a string
string.contains(new RegExp(r'[A-Z]'));    // true

Example 2: Flutter get each letter from string

String mystring = 'Hello World';

  print('${mystring[0]}');