description

# split method Null safety

List<String> split (

1. Pattern pattern

)

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();

## Implementation

    List<String> split(Pattern pattern);