Dart Convert Library

The Dart convert library is a powerful tool for encoding and decoding data in various formats. It provides efficient methods for working with JSON, UTF-8, and Base64 conversions, making it an essential part of many Dart applications.

JSON Conversion

JSON (JavaScript Object Notation) is a popular data format used for data exchange. The convert library offers simple methods to convert between Dart objects and JSON strings.

Encoding to JSON

import 'dart:convert';

void main() {
  Map person = {
    'name': 'John Doe',
    'age': 30,
    'city': 'New York'
  };

  String jsonString = jsonEncode(person);
  print(jsonString);
}
    

This example demonstrates how to convert a Dart Map to a JSON string using the jsonEncode() function.

Decoding from JSON

import 'dart:convert';

void main() {
  String jsonString = '{"name":"Jane Smith","age":25,"city":"London"}';

  Map person = jsonDecode(jsonString);
  print(person['name']); // Output: Jane Smith
}
    

This code snippet shows how to parse a JSON string into a Dart object using the jsonDecode() function.

UTF-8 Encoding and Decoding

UTF-8 is a widely used character encoding capable of representing any Unicode character. The convert library provides methods for encoding and decoding UTF-8 strings.

import 'dart:convert';

void main() {
  String originalString = 'Hello, 世界!';
  List encodedBytes = utf8.encode(originalString);
  String decodedString = utf8.decode(encodedBytes);

  print('Encoded bytes: $encodedBytes');
  print('Decoded string: $decodedString');
}
    

This example illustrates UTF-8 encoding and decoding using the utf8.encode() and utf8.decode() methods.

Base64 Encoding and Decoding

Base64 encoding is commonly used to encode binary data for transmission over text-based protocols. The convert library simplifies Base64 operations in Dart.

import 'dart:convert';

void main() {
  String originalString = 'Dart is awesome!';
  String base64String = base64Encode(utf8.encode(originalString));
  String decodedString = utf8.decode(base64Decode(base64String));

  print('Base64 encoded: $base64String');
  print('Decoded string: $decodedString');
}
    

This code demonstrates Base64 encoding and decoding using the base64Encode() and base64Decode() functions.

Best Practices

• Always handle potential exceptions when working with JSON conversions.
• Use try-catch blocks to gracefully handle encoding and decoding errors.
• When working with large data sets, consider using streaming APIs for better performance.
• Validate input data before encoding to ensure proper format and structure.

Conclusion

The Dart convert library is a versatile tool for handling various data conversions. By mastering its functions, developers can efficiently work with JSON, UTF-8, and Base64 encodings in their Dart applications. For more advanced usage, explore the Dart async library to handle conversions asynchronously.