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.

main.dart

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.

main.dart

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.

main.dart

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.

main.dart

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.

main.dart

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.

Author

My name is Jan Bodnar, and I am a passionate programmer with extensive programming experience. I have been writing programming articles since 2007. To date, I have authored over 1,400 articles and 8 e-books. I possess more than ten years of experience in teaching programming.

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