Dart:
Converting a string to lower case

How to:

In Dart, you can convert a string to lowercase using the toLowerCase() method provided by the String class. This method returns a new string with all uppercase characters converted to lowercase. Let’s see how this works with a simple example:

void main() {
  String originalString = "Hello, World!";
  String lowerCaseString = originalString.toLowerCase();

  print(lowerCaseString);  // Output: hello, world!
}

Dart does not require external libraries for basic string manipulation tasks, including converting to lowercase, as the standard library’s String class is quite comprehensive. However, for more complex manipulations involving locale-specific rules, you might consider the intl package, which provides internationalization and localization facilities, including case conversion based on locale:

To use intl, add it to your pubspec.yaml file:

dependencies:
  intl: ^0.17.0

Then, you can use the toLocaleLowerCase() method to convert a string to lowercase based on specific locales:

import 'package:intl/intl.dart';

void main() {
  String originalString = "İstanbul";
  
  // Turkish Locale
  print(Intl.withLocale('tr', () => originalString.toLowerCase())); // Output: istanbul
  
  // Default Locale (en)
  print(originalString.toLowerCase()); // Output: i̇stanbul
}

In this example, notice how the Turkish locale correctly handles the dotless ‘i’, showcasing the importance of locale-aware transformations in internationalized applications.