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split abstract method
List<String> split(Splits the string at matches of pattern and returns a list of substrings.
Finds all the matches of pattern in this string, and returns the list of the substrings between the matches.
var string = "Hello world!";
string.split(" ");                      // ['Hello', 'world!'];
  Empty matches at the beginning and end of the strings are ignored, and so are empty matches right after another match.
var string = "abba";
string.split(new RegExp(r"b*"));        // ['a', 'a']
                                        // not ['', 'a', 'a', '']
  If this string is empty, the result is an empty list if pattern matches the empty string, and it is [""] if the pattern doesn't match.
var string = '';
string.split('');                       // []
string.split("a");                      // ['']
  Splitting with an empty pattern splits the string into single-code unit strings.
var string = 'Pub';
string.split('');                       // ['P', 'u', 'b']
string.codeUnits.map((unit) {
  return new String.fromCharCode(unit);
}).toList();                            // ['P', 'u', 'b']
  Splitting happens at UTF-16 code unit boundaries, and not at rune boundaries:
// String made up of two code units, but one rune.
string = '\u{1D11E}';
string.split('').length;                 // 2 surrogate values
  To get a list of strings containing the individual runes of a string, you should not use split. You can instead map each rune to a string as follows:
string.runes.map((rune) => new String.fromCharCode(rune)).toList();
  Source
List<String> split(Pattern pattern);
  © 2012 the Dart project authors
Licensed under the Creative Commons Attribution-ShareAlike License v4.0.
 https://api.dartlang.org/stable/1.24.3/dart-core/String/split.html