Dart split string
last modified January 28, 2024
In this article we show how to split strings in Dart language.
List<String> split(Pattern pattern)
The split function splits the string at matches of the supplied
pattern and returns a list of substrings. The pattern may be a string or a
regular expression.
Dart split string simple example
The following example splits a sentence into words.
void main() {
final text = "There is an old hawk in the sky";
final words = text.split(' ');
for (final word in words) {
print("${word} has ${word.length} characters");
}
}
In the program, we split a sentence into a list of words by a space character.
final text = "There is an old hawk in the sky";
We have a text message.
final words = text.split(' ');
We split the message into words. The pattern is a space.
for (final word in words) {
print("${word} has ${word.length} characters");
}
We go over the list of words and print them and their size to the console.
$ dart main.dart There has 5 characters is has 2 characters an has 2 characters old has 3 characters hawk has 4 characters in has 2 characters the has 3 characters sky has 3 characters
Dart split string with regex
In the next example, we split a string using a regular expression.
void main() {
final text = "falcon,eagle,forest;sky,cloud,water;rock,wind";
final words = text.split(RegExp(r"[,;]"));
for (final word in words) {
print(word);
}
}
In the example, we have a text in which words are separated by two characters: command and semicolon. We want to split the string by both characters.
final words = text.split(RegExp(r"[,;]"));
We use a simple regular expression to split by both characters.
$ dart main.dart falcon eagle forest sky cloud water rock wind
Dart split string by spaces
In the following example, we split string by spaces.
void main() {
final text = "There are\t\t many clouds in the \n sky";
final pattern = RegExp(r"\s+");
final words = text.split(pattern);
print(words);
for (final word in words) {
print(word);
}
}
In the example, we have a string with multiple white spaces: tabs, single spaces and new lines.
final pattern = RegExp(r"\s+");
We use a regular expression which works for one or more white spaces.
$ dart main.dart [There, are, many, clouds, in, the, sky] There are many clouds in the sky
Dart split runes
The split function does not work for runes.
import "dart:io";
void main() {
final msg = "one 🐘 and three 🐋";
final els = msg.split("");
for (final e in els) {
stdout.write("${e} ");
}
print('\n----------------------');
for (final rune in msg.runes) {
stdout.write("${String.fromCharCode(rune)} ");
}
}
In order to enumerate runes, we need to use the runes property.
$ dart runes.dart o n e � � a n d t h r e e � � ---------------------- o n e 🐘 a n d t h r e e 🐋
Dart splitMapJoin
The splitMapJoin function splits the string, converts its parts,
and combines them into a new string.
void main() {
final text = '''Foxes are omnivorous mammals belonging to several genera
of the family Canidae. Foxes have a flattened skull, upright triangular ears,
a pointed, slightly upturned snout, and a long bushy tail. Foxes live on every
continent except Antarctica. By far the most common and widespread species of
fox is the red fox.''';
final res = text.splitMapJoin(RegExp(r"[fF]ox(es)?"),
onMatch: (m) => '*${m.group(0)}*');
print(res);
}
In the program, we use the splitMapJoin function to mark all
occurences of the fox word with star characters.
final res = text.splitMapJoin(RegExp(r"[fF]ox(es)?"),
onMatch: (m) => '*${m.group(0)}*');
We supply a regular expression that matches all occurences of the word fox,
including the plural form and the form with the capital F letter. The
onMatch callback is called on each match. It is also possible to
utilize the onNonMatch callback.
$ dart main.dart *Foxes* are omnivorous mammals belonging to several genera of the family Canidae. *Foxes* have a flattened skull, upright triangular ears, a pointed, slightly upturned snout, and a long bushy tail. *Foxes* live on every continent except Antarctica. By far the most common and widespread species of *fox* is the red *fox*.
Source
Dart split String method - language reference
In this article we have covered splitting strings in Dart.
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